Negative Asymmetry Research Articles

Deformation of volatility curves of the Russian stock market on the example of margined options on futures contracts on the RTS index

We reassess the Russian stock market behavior in terms of the relationship between risk parameters and return on assets in connection with global structural changes in 2022. The subject of this study is volatility curves calculated from quotes of exchange options on RTS index futures. The purpose of the study is to analyze the relationship between volatility curves and the distribution of returns in 2015–2022, to analyze changes in the structure of this relationship in 2022, to assess the applicability of the GARCH model and to develop new investment and hedge strategies on the Russian stock market. The issue of interpreting the dynamics of volatility curves is disputable however, it was theoretically developed in the theory of valuation of derivative financial instruments. As a result of the study, unrelated structures of the distribution of returns and volatility curves for the RTS composite index were found throughout the entire period concerned, regardless of the presence of external shocks. It is concluded that in the Russian stock market, investors prefer protective options rather than speculative ones, despite the negative asymmetry of the distribution of RTS index returns. And despite the greater weight of positive returns in their distribution in each period under consideration, due to the technical features of the functioning of return indicators, the negative asymmetry of the return distribution does not necessarily correlate with growing volatility curves.

Negative Asymmetric Response of Pantropical Gross Primary Productivity to Precipitation Anomalies

AbstractThe carbon sink in pantropical biomes play a crucial role in modulating the inter‐annual variations of global terrestrial carbon balance and is threatened by extreme climate events. However, it has not been carefully examined whether an increase in tropical gross primary productivity (GPP) can compensate the decrease during precipitation anomalies. Using the asymmetry index (AI) and multiple GPP products, we assessed responses of pantropical GPP to precipitation anomalies during 2001–2022. Positive AI indicates that GPP increases are greater than GPP decreases during precipitation anomalies, and vice versa. Our results showed an average negative pantropical GPP asymmetry, that is, GPP decreases exceeded the GPP increases during precipitation anomalies. In addition, a positive AI was found in tropical hyper‐arid and arid regions, which is opposite to the negative AI observed in tropical semi‐arid, sub‐humid, and humid regions. This suggest that tropical GPP asymmetry changes from positive to negative as the moisture increases. Notably, a significant decreasing trend of negative AI was observed over the entire tropical region, indicating that the negative effect of inter‐annual precipitation variations on pantropical vegetation productivity has enhanced. Considering the model predicted increasing climate variability and extremes, the negative impact of precipitation variability on tropical carbon cycle may continue to intensify. Lastly, the divergence in AI estimates among multiple GPP products highlight the need to further improve our understanding of the response of tropical carbon cycle to climate changes, especially for the tropical humid regions.

Russia – Africa: The Role of the Media in the Process of Cross-Cultural Communication

The article is devoted to the role of mass media in the process of intercultural communication with African countries. Due to the growing sanctions pressure from the European Union and the United States, Russia is looking for alternative political and economic allies, which it seeks to fi nd among the countries of the African continent. In this context, the issue of intercultural communication with this region is becoming increasingly important. The relevance of the study is due to the fact that the image of African states in the leading Russian print media does not correspond to Russia’s stated political ambitions towards these countries. It is observed that the image of the partner countries in the Russian media is not presented fully enough, with an emphasis on the negative side. The article substantiates the idea that the awareness of Russian residents about the culture of Africa is an important component of successful communication. The study aims to evaluate the functions of the media in the process of forming the image of a number of countries and, in accordance with this, analyze the image of Africa being formed in the Russian media fi eld. The novelty of the research lies in presenting a new perspective on the role of the media in the process of intercultural communication. The theoretical basis was scientifi c articles, documents published by public organizations and public authorities. The method of content analysis is used as an approach to the study of media texts. The research materials were published by the major Russian online media “Argumenty i Fakty (Arguments and Facts)” and “RIA Novosti”. The results show the presence of a negative asymmetry in the representation of the image of Africa. The prospect of this study is further and more detailed monitoring of the tone of media publications about Africa and the formation of specifi c proposals for correcting information policy. Keywords: coverage policy, image of Africa, intercultural communication, prospects for interaction, role of the media

Tailoring the surface topography and crystallinity of EuMnO3 films: A study on sintering effects

We obtained EuMnO3 films through a sol-gel process at varying temperatures, aiming to investigate spatial layout variations influenced by different sintering temperatures. Our results indicate that films adopt an orthorhombic structure when sintered between 800 °C and 850 °C, accompanied by a reduction in nanocrystal size during annealing. Surface analysis reveals that films processed at higher temperatures exhibit increased roughness, negative asymmetry, heightened kurtosis, elevated peak densities, and more distinct peak forms. Furthermore, these films display surfaces with greater anisotropy and lower spatial frequencies compared to those sintered at lower temperatures. Nevertheless, fractal analysis uncovers that both the EuMnO800 and EuMnO850 samples showcase heightened spatial complexity, a more uniform nanotexture, optimal surface porosity, and improved topographic consistency. The findings suggest that films sintered at 800 °C display a spatial arrangement with superior topographic qualities, rendering them potentially valuable for the advancement of semiconductor films derived from perovskite rare-earth oxides for various technological applications.

Temporal Complementarity Analysis of Wind and Solar Power Potential for Distributed Hybrid Electric Generation in Chile

We evaluate the temporal complementarity in daily averages between wind and solar power potential in Chile using Spearman’s correlation coefficient. We used hourly wind speed and solar radiation data for 176 geographic points from 2004 to 2016. The results allow us to identify four zones: Zone A1 on the coast and in the valleys in the north of Chile between latitudes 18° S and 36° S, with moderate positive correlation; Zone A2 in the north Andes between latitudes 25° S and 33° S, with weak negative correlation; Zone B in the center-south part of the country between latitudes 36° S and 51° S with moderate negative correlation; and Zone C in the south, between latitudes 51° S and 55° S with null or weak positive correlation. On the one hand, the interannual analysis shows that Zone A1 keeps uniform correlation values with negative asymmetry, i.e., higher correlation values. On the other hand, there is positive asymmetry in most of the years in Zone A2, i.e., lower (or negative) values of correlation. Zone B shows an interannual oscillation of the median correlation, while Zone C shows a larger dispersion in the interannual results. Significance analysis shows that 163 out of the 176 points are statistically significant, while Zones A1, A2, and B have significant correlations, with Zone C being marginally significant. The results obtained are relevant information for further studies on the location of hybrid generation facilities. We expect our methodology to be instrumental in Chile’s energetic transition to a 100% renewable generation matrix.

Tracing the dynamic impact of energy transitions on equity market volatility in an era of financial turbulence

This study investigates the dynamic relationship between the shift towards clean energy and stock market fluctuations, covering the period from January 2004 to August 2021 by applying time-varying parameters vector autoregressions (TVP-VAR). The results reported strong spillovers between clean energy markets and stocks, while dirty ones demonstrated disconnected spillovers. Asymmetry in the spillovers detected dominance of negative (bad) spillovers due to various uncertain economic and financial circumstances. The most significant negative (bad) events tracked in time-varying attributes are the global financial crisis, European Debt Crisis, Shale Oil Crisis, Brexit, US interest rate agenda, and the COVID-19 pandemic. Meanwhile, negative asymmetries prevailed in time-varying analysis, echoing the pre-eminence of negative crisis periods. We identified clean energy markets and stocks as net spillover emitters and dirty energy markets as net recipients. These findings have profound implications for a range of stakeholders, including investors, policymakers, and market participants, offering valuable insights for portfolio diversification and risk management strategies amidst the ongoing energy paradigm shift.

Predictive modeling of antidepressant efficacy based on cognitive neuropsychological theory

BackgroundWe aimed to develop a clinical predictive model based on the cognitive neuropsychological (CNP) theory and machine-learning to examine SSRI efficacy in the treatment of MDD. MethodsBaseline assessments including clinical symptoms (HAMD, HAMA, BDI, and TEPS scores), negative biases (NEO-PI-R-N and NCPBQ scores), sociodemographic characteristics (social support and SES), and a 5-min eye-opening resting-state EEG were completed by 69 participants with first-episode major depressive disorder (MDD) and 36 healthy controls. The clinical symptoms and negative bias were again assessed after an 8-week treatment of depression with selective serotonin reuptake inhibitors (SSRIs). A multi-modality machine-learning model was developed to predict the effectiveness of SSRI antidepressants. ResultsAt baseline, we observed significant differences between MDD patients and healthy controls in terms of social support, clinical symptoms, and negative bias characteristics (p < 0.001). A negative association was found (p < 0.05) between neuroticism and alpha asymmetry in both the central and central-parietal areas, as well as between negative cognitive processing bias and alpha asymmetry in the parietal region. Compared to responders, non-responders exhibited less negative cognitive processing bias and greater alpha asymmetry in both central and central-parietal regions. Importantly, we developed a multi-modality machine-learning model with 83 % specificity using the above salient features. ConclusionsResearch results support the CNP theory of depression treatment. To some extent, the multimodal clinical model constructed based on the CNP theory effectively predicted the efficacy of this treatment in this population. LimitationsSmall sample and only focus on the mechanisms of delayed-onset SSRI treatment.

Influence of generalist stingless bees on the structure of mutualistic flower–pollinator networks in the tropics: Temporal variation

Abstract Stingless bees (Meliponini) are expected to play a central role in structuring mutualistic networks in the Neotropics, as they are generalist and often abundant pollinators. Living in populous social colonies with a perennial life cycle, they require continuous large amounts of resources and often forage on abundant flowerings such as mass‐flowering throughout the year. In this field research, we seek to understand how temporal variations on foraging activity of stingless bees and abundance of mass‐flowering partner plants affect the topology of the plant–pollinator mutualistic networks. The networks were compared between spring and summer, periods of high and low abundances of flowerings and mass‐flowering, respectively. Bees were sampled on flowers, in replicates of floodplain fields in Atlantic Forest of southern Brazil. Interactions with partner plants were considered effective only when bees had pollen on their bodies (potential pollinators). Through analysis of pollen grains attached to their bodies, several topological metrics of networks and functional categories were obtained. The robustness or networks resistance to secondary species loss due to simulated focal species extinction was also measured. The networks maintained similar general structure throughout the year (high nestedness, moderate modularity and connectance, low community‐level specialisation and negative dependency asymmetry). Particularly, nestedness and dependency asymmetry did not change between the two seasons. Community‐level specialisation was higher in summer, contrary to expectations, when there was a collapse in the supply of floral resources and also a reduction in the abundance and foraging pressure of stingless bees. As there was also a greater number of specialist pollinators in summer, the hypothesis of temporal displacement due to foraging pressure from generalists was proposed. At the same time, stingless bees oscillated between network hubs in spring and connectors in summer, reflecting the variation in their abundance between these two seasons. In spring, the greater concentration of foraging by these generalists in the abundant mass‐flowering probably attenuated their diffuse competitive pressure on all other pollinators, even though the foraging overlap was higher in this period. In this period of high abundance of floral resources, specialist pollinators capable of expanding the realised niche are active. Based on recent theoretical conclusions of dynamic model of mutualistic networks structure that incorporated effects of inter‐specific competition and adaptive foraging, we argue that the adaptive foraging of generalist and abundant stingless bees contributes in an important way to the high nestedness and robustness of networks, which ultimately favour the coexistence of species in the long term. Particularly, taking the high intra‐annual turnover of bee and plant species between the two seasons, and the similar floral constancy of both generalist stingless bees and specialist pollinators, we also infer that stingless bees act as generalised pollinators in the networks rewiring throughout the year.

Johnson-Mehl-Avrami kinetics as a universal description of crystallization in glasses?

Applicability of the Johnson-Mehl-Avrami (JMA) model beyond the typical range of the negative asymmetries of the crystallization peak was tested by means of theoretical simulations. Using the solid-state kinetic equation with implemented temperature dependences of either activation energy E or pre-exponential factor A, it was shown that the originally monotonically increasing transformation rate constant changes its evolution with temperature to a non-monotonous course, exhibiting a broad maximum. If the crystallization process following the non-isothermal JMA kinetics proceeds near this maximum, the asymmetry of the corresponding kinetic peak can gradually change to significantly positive values. Of particular interest are the cases with the JMA kinetic exponent mJMA ≥ 2, where the asymmetry of the JMA peaks changes with increasing heating rate from the typical negative values to largely positive values – such crystallization behavior was indeed observed for several chemically diverse materials (polymers, small organic molecules, chalcogenide and oxide glasses).

Differential responses of soil extracellular enzyme activity and stoichiometry to precipitation changes in a poplar plantation

Changes in precipitation patterns can significantly affect belowground processes. Although soil extracellular enzymes play a vital role in several biogeochemical processes, our knowledge of how precipitation changes affect soil extracellular enzyme activity (EEA) and stoichiometry remains insufficient. In this study, we investigated the activities of C-acquiring enzyme (β-1,4-glucosidase), N-acquiring enzymes (β-N-acetylglucosaminidase and leucine aminopeptidase), and P-acquiring enzyme (acid phosphatase) under different precipitation scenarios [ambient precipitation (CK), 30% decrease in precipitation (moderate DPT), 50% decrease in precipitation (extreme DPT), 30% increase in precipitation (moderate IPT), and 50% increase in precipitation (extreme IPT)] in a poplar plantation. We found soil EEA exhibited more pronounced increases to moderate IPT compared to moderate DPT (positive asymmetry), the opposite trend (negative asymmetry) was observed under extreme precipitation; whereas soil EEA C:N:P stoichiometry exhibited negative asymmetry at moderate precipitation changes, and exhibited positive asymmetry at extreme precipitation changes. Under moderate precipitation changes, the asymmetry of soil EEA was mainly regulated by asymmetries of respective microbial biomass and litter mass; the asymmetry of soil EEA stoichiometry was mainly regulated by asymmetries of respective soil stoichiometric ratios and litter mass. Furthermore, under extreme precipitation changes, the asymmetries of soil EEA and stoichiometry were best explained by the asymmetry of soil moisture. Our results provide the first evidence of double asymmetric responses of soil EEA and stoichiometry to precipitation changes and highlight the need to consider this asymmetry when modeling the dynamics of biogeochemical cycling in forest ecosystems.

Nitrogen rather than phosphorous addition alters the asymmetric responses of primary productivity to precipitation variability across a precipitation gradient on the northern Tibetan Plateau

Understanding the response of alpine grassland productivity to precipitation fluctuations is essential for assessing the future changes of ecosystem services. However, the underlying mechanism by which grassland productivity responds to wet and dry years after nitrogen (N) or/and phosphorus (P) nutrient addition remains unclear. In this study, we investigated the dynamics of plant communities based on eight-year N or/and P addition gradient experiments in four grassland types across a precipitation gradient on the north Tibetan Plateau. The asymmetry index (AI) was used to evaluate the responses of aboveground net primary productivity (ANPP) to precipitation fluctuations where AI > 0 indicates a greater increase of ANPP in wet years compared to the decline in dry years, and AI < 0 indicates a greater decline of ANPP in dry years compared to the increase in wet years. Our results showed that the AI values at community level in four natural grasslands were non-significant trend across the precipitation gradient, and showed slightly negative asymmetry, suggesting that the increase of ANPP in wet years was less than the decrease in dry years. N addition resulted in a significant decrease in community-level AI values with increasing mean annual precipitation (MAP), indicating that improved nutrient availability may favor the recovery of productivity in drier grasslands in wet years. At the functional group level, nutrient addition resulted in a significant decrease in the AI values of grasses and legumes and an increase in the AI values of forbs as MAP increased. Furthermore, the coupling of nutrients with precipitation can influence the productivity responses to precipitation changes by affecting soil nutrient availability and species richness. This research provides new insights into better predicting vegetation activity on N deposition rates and precipitation changes exacerbated in the context of climate change.

C:N:P stoichiometry of plants, soils, and microorganisms: Response to altered precipitation.

Precipitation changes modify C, N, and P cycles, which regulate the functions and structure of terrestrial ecosystems. Although altered precipitation affects above- and belowground C:N:P stoichiometry, considerable uncertainties remain regarding plant-microbial nutrient allocation strategies under increased (IPPT) and decreased (DPPT) precipitation. We meta-analyzed 827 observations from 235 field studies to investigate the effects of IPPT and DPPT on the C:N:P stoichiometry of plants, soils, and microorganisms. DPPT reduced leaf C:N ratio, but increased the leaf and root N:P ratios reflecting stronger decrease of P compared with N mobility in soil under drought. IPPT increased microbial biomass C (+13%), N (+15%), P (26%), and the C:N ratio, whereas DPPT decreased microbial biomass N (-12%) and the N:P ratio. The C:N and N:P ratios of plant leaves were more sensitive to medium DPPT than to IPPT because drought increased plant N content, particularly in humid areas. The responses of plant and soil C:N:P stoichiometry to altered precipitation did not fit the double asymmetry model with a positive asymmetry under IPPT and a negative asymmetry under extreme DPPT. Soil microorganisms were more sensitive to IPPT than to DPPT, but they were more sensitive to extreme DPPT than extreme IPPT, consistent with the double asymmetry model. Soil microorganisms maintained stoichiometric homeostasis, whereas N:P ratios of plants follow that of the soils under altered precipitation. In conclusion, specific N allocation strategies of plants and microbial communities as well as N and P availability in soil critically mediate C:N:P stoichiometry by altered precipitation that need to be considered by prediction of ecosystem functions and C cycling under future climate change scenarios.

Do world stock markets “jump” together? A measure of high-frequency volatility risk spillover networks

We provide a systematic framework for studying high-frequency risk connectedness among world stock markets. Our framework, based on high-frequency realized volatility decompositions, TVP-VAR networks, and innovative extensions, shows risk connectedness among 16 world stock markets with respect to seven levels of high-frequency volatility. The findings are as follows. First, all seven levels of risk connectedness are significantly enhanced in response to extreme event shocks. The COVID-19 event led to a peak in total connectedness, and the event changed the structure of the spillover network the most, with markets in Asia-Pacific continent being the most affected by this event. The transmission of information is unique to different levels, with the “bad” volatility level being the strongest and the jump volatility level being the most sensitive. Second, there is a geographical effect on stock market performance, with the U.S. stock market being the most stable and dominant. The mainland Chinese stock market is the most vulnerable to volatility, being a net receiver of volatility 91.04% of the time. Third, we provide evidence of asymmetric spillovers at the level of “good-bad” volatility and “good-bad” jumps. The similarity between these two asymmetric effects is that the negative asymmetry is substantial and more pronounced in response to risky event shocks. The difference is that the asymmetry of “good-bad” jumps reflects more strongly the impact of crisis event shocks. Seven countries are dominated by pessimism most of the time, with the UK, Canada and Mexico being the main transmitters of pessimism, and their ability to transmit pessimism has increased during the crisis.

Fraser-Suzuki function as an essential tool for mathematical modeling of crystallization in glasses

The performance of the Fraser-Suzuki function during mathematic deconvolution of crystal growth kinetic processes was extensively analyzed based on theoretical simulations. Regarding pure imitation, the Fraser-Suzuki function well describes processes with moderate negative asymmetry of a3 ≈ <−0.6; −0.2>. Considering the ability of the Fraser-Suzuki function to transfer the kinetic information during the mathematic deconvolution (i.e., performance in the procedure: kinetic signal → fit by Fraser-Suzuki function → kinetic analysis of the Fraser-Suzuki data-curve), it is very well suited for separating processes following single-exponent kinetic models such as the nucleation-growth Johnson-Mehl-Avrami-Kolmogorov model or the nth order reaction model. For the nth order autocatalytic model, the magnitude of errors depends directly on the exponent nNC. Reliable performance of the Fraser-Suzuki function is achieved when resulting nNC falls in <0; 1.2> interval. Combining the Fraser-Suzuki mathematic deconvolution with the consequent kinetic analysis utilizing the nth order autocatalytic model is highly recommended.

Asymmetries of frequency splittings of dipolar mixed modes: A window on the topology of deep magnetic fields

Context. Space asteroseismology is revolutionizing our knowledge of the internal structure and dynamics of stars. A breakthrough is ongoing with the recent discoveries of signatures of strong magnetic fields in the core of red giant stars. The key signature for such a detection is the asymmetry these fields induce in the frequency splittings of observed dipolar mixed gravito-acoustic modes. Aims. We investigate the ability of the observed asymmetries of the frequency splittings of dipolar mixed modes to constrain the geometrical properties of deep magnetic fields. Methods. We used the powerful analytical Racah-Wigner algebra used in quantum mechanics to characterize the geometrical couplings of dipolar mixed oscillation modes with various realistically plausible topologies of fossil magnetic fields. We also computed the induced perturbation of their frequencies. Results. First, in the case of an oblique magnetic dipole, we provide the exact analytical expression of the asymmetry as a function of the angle between the rotation and magnetic axes. Its value provides a direct measure of this angle. Second, considering a combination of axisymmetric dipolar and quadrupolar fields, we show how the asymmetry is blind to the unraveling of the relative strength and sign of each component. Finally, in the case of a given multipole, we show that a negative asymmetry is a signature of non-axisymmetric topologies. Conclusions. Asymmetries of dipolar mixed modes provide a key bit of information on the geometrical topology of deep fossil magnetic fields, but this is insufficient on its own. Asteroseismic constraints should therefore be combined with spectropolarimetric observations and numerical simulations, which aim to predict the more probable stable large-scale geometries.

Forgive or complain: Interpersonal distance modulates reactive attitudes and neural responses toward wrongdoers

While the effect of interpersonal distance on forgiveness has been investigated over the past few years, it remains unclear whether this facilitating effect holds even when measured implicitly. Meanwhile, though cognitive control and the corresponding prefrontal cortex play a prominent role in forgiveness processing, the neural mechanism underlying forgiveness toward varied wrongdoers is largely unexplored. Here, forty-two participants initially underwent noise offense either from their friend or stranger, followed by a word identification test to examine their implicit attitude, during which they were presented with word-name combinations and required to categorize forgive- or complain-label words while ignoring the names of their friends or strangers below. A shorter reaction time reflects more congruence with one’s implicit attitude. Electroencephalogram was recorded during the word identification test. Behaviorally, while individuals reacted faster to forgive-friend relative to complain-friend pairings, no such reaction bias was found for the stranger-wrongdoer, which suggests that individuals were more inclined to forgive someone close. Regarding the EEG/ERP results, forgive-friend elicited lower alpha oscillation and more negative frontal alpha asymmetry (FAA) value than complain-friend combinations, suggesting increased and dominant activity in the right prefrontal network during forgiveness toward friends. Whereas complain- relative to forgive-stranger combinations elicited larger P3 amplitudes, suggesting a neural encoding bias to information associated with complaints about stranger-wrongdoer. These multimodal findings provide evidence for the benefits of closeness in forgiveness and shed light on the neural mechanisms underlying forgiveness toward different types of wrongdoers.

Asymmetry Between Positive and Negative Phases of the Pacific Meridional Mode: A Contributor to ENSO Transition Complexity

AbstractThe Pacific Meridional Mode (PMM) plays a critical role in affecting El Niño‐Southern Oscillation (ENSO). This study examines the phase asymmetry of PMM events triggered by tropical and extratropical forcings, namely successive and stochastic events, respectively. It is shown that successive events exhibit negative asymmetry due to stronger trigger in the negative phase, while stochastic events display positive asymmetry due to stronger growth in the positive phase. The opposite phase asymmetry of two types of events respectively results in more frequent persistent La Niña events than El Niño events and more frequent episodic El Niño events than La Niña events, which increase ENSO transition complexity. This research provides a comprehensive understanding of PMM asymmetry and reconciles conflicting perspectives from previous studies. Additionally, the newly proposed contribution of positively asymmetric stochastic PMM events to more frequent episodic El Niño events in this study may enhance our comprehension of ENSO transition complexity.

ECONOMICS OF THE INFORMATION SECTOR ON THE EXAMPLE OF POSTAL SERVICES

The implications of the information sector resulted in the creation of many new companies, but also development of certain sectors within existing companies that needed a new strategy for growth and development in the market. Corporations, in order to achieve higher overall level of efficiency and profitability are reaching for additional ways of strengthening individual sectors, i.e. through networking, activating those sectors they consider to have potential for further development. Thus, the information sector became a core activity that offered the potential for companies to explore new directions or even support the strengthening of already existing activities. The sales sector, especially in those corporations with a significant retail component, discovers through the economy of the information sector new sales channels or even new market niches that were previously inaccessible without networking. The operation of the information sector is based on various forms of networking, creating network effects that enable companies to achieve above-average business results, by utilizing the potential of designed activities. This paper analyses the activities of Hrvatska pošta d.d. and how networking has successfully multiplied the potential of that company, creating a new market segment. The traffic variable of the Yellow Click was analyzed using descriptive statistics. In the analysis, the years 2018 to 2022 were taken, so the number of observed years was 5. The table lists the minimum, maximum value, arithmetic mean, median, and value of the first and third quartiles. The mode does not exist on the observed data set. The variation range is the year with the most Yellow Click sales and the year with the least sales. The coefficient of asymmetry α3 is -1.018, which indicates a negative asymmetry of the distribution, while the coefficient of roundness α4 is 1.958, which indicates that the distribution of variables is more elongated than normal, that is, it is less flattened than with a normal distribution. The relationship between the variables yellow click and retail sales was analyzed according to the data from table number 1.6. The data for the year 2022 were excluded from the analysis, so the data from 2018 - 2021 were taken into the analysis, because in 2022 the sales growth trend was interrupted by the yellow click due to the introduction of the covid certificate, so that year was excluded from the analysis of the observed series of data as a clearer insight into the data could be obtained. A regression and correlation analysis of the yellow click turnover and retail turnover variables was carried out.

The Asymmetric Impact of Energy’s Paradigm Transition on Environmental Degradation: a Macroeconomic Evidence from Latin American and the Caribbean Countries

The main objective of this study is to identify the impact of the energy paradigm transition on the environmental degradation of eighteen Latin American and Caribbean (LAC) countries. To this end, a panel non-linear autoregressive distributed lag (PNARDL) in the form of an unrestricted error correction model (UECM) and a period from 1990 to 2019 were used. The empirical results indicated that the variable economic growth in both the short- and long-run have an increase of 0.6994 and 0.3192, respectively, and the variable public capital stock in the short-run has an increase of 0.0176 in CO2 emissions. However, the positive and negative asymmetry of the variable ratio of renewable energy in the short-and long-run has a decrease of −0.1320 (on positive variations) and −0.1131 (on negative variations) in the short run and −0.0364 (on positive variations) and −0.0783 (on negative variations) in the long run on CO2 emissions. The capacity of the ratio of renewable/fossil energy consumption to reduce environmental degradation is compatible with the renewable energy technological efficiency that produces more clean energy and fewer emissions. That was also in line with the increasing participation of renewable energy sources in the energy matrix in the LAC countries.

Analyses of Head-Impulse Tests in Patients With Posterior Circulation Stroke and Vestibular Neuritis.

The interpretation of video head-impulse tests (video-HITs) can often be complicated, limiting their clinical utility in acute vestibular syndrome. We aimed to determine video-HIT findings in patients with posterior circulation strokes (PCSs) and vestibular neuritis (VN). We retrospectively analyzed the results of video-HITs in 59 patients with PCS. Irrespective of the actual lesion revealed later on MRIs, ipsilateral and contralateral sides were assigned according to the direction of slow phase of spontaneous nystagmus (SN). Then, the patterns of video-HIT findings were classified according to the vestibulo-ocular reflex (VOR) gain for the horizontal canals; (1) ipsilaterally positive, (2) contralaterally positive, (3) bilaterally normal, and (4) bilaterally positive. The abnormal responses were further defined into (5) wrong-way saccades, (6) perverted, and (7) early acceleration followed by premature deceleration. We also analyzed the asymmetry of the corrective saccadic amplitude between the sides, calculated from the sum of cumulative saccadic amplitudes on both sides. The results were compared with video-HIT results from 71 patients with VN. Video-HITs were normal in 32 (54%), ipsilaterally positive in 11 (19%), bilaterally positive in 10 (17%), and contralaterally positive in 6 (10%) patients with PCS. Wrong-way saccades were more frequently observed in VN than in PCS (31/71 [44%] vs 5/59 [8%], p < 0.001). Saccadic amplitude asymmetry was greater in VN than in PCS (median 100% [interquartile range 82-144, 95% CI 109-160] vs 0% [-29 to 34, -10 to 22, p < 0.001]). When differentiating VN from PCS, the sensitivity was 81.7%, and specificity was 91.5% at the cutoff value of 71% for saccadic amplitude asymmetry with an area under the curve (AUC) of 0.91 (95% CI 0.86-0.97). The AUC for saccadic amplitude asymmetry was larger than that for the ipsilateral VOR gain (p = 0.041) and other parameters. Patients with PCS may show various head-impulse responses that deviate from the findings expected in VN, which include normal, contralaterally positive, and negative saccadic amplitude asymmetry (i.e., greater cumulative saccadic amplitude contralaterally). A thorough analysis of corrective saccades in video-HITs can improve the differentiation of PCS from VN even before MRIs.