Central Region Research Articles

Impaired brain-heart axis in focal epilepsy: Alterations in information flow and implications for seizure dynamics

Abstract This study delves into functional brain-heart interplay (BHI) dynamics during interictal periods before and after seizure events in focal epilepsy. Our analysis focuses on elucidating the causal interaction between cortical and autonomic nervous system (ANS) oscillations, employing electroencephalography and heart rate variability series. The dataset for this investigation comprises 47 seizure events from 14 independent subjects, obtained from the publicly available Siena Dataset. Our findings reveal an impaired brain-heart axis especially in the heart-to-brain functional direction. This is particularly evident in bottom-up oscillations originating from sympathovagal activity during the transition between preictal and postictal periods. These results indicate a pivotal role of the ANS in epilepsy dynamics. Notably, the brain-to-heart information flow targeting cardiac oscillations in the low-frequency band does not display significant changes. However, there are noteworthy changes in cortical oscillations, primarily originating in central regions, influencing heartbeat oscillations in the high-frequency band. Our study conceptualizes seizures as a state of hyperexcitability and a network disease affecting both cortical and peripheral neural dynamics. Our results pave the way for a deeper understanding of BHI in epilepsy, which holds promise for the development of advanced diagnostic and therapeutic approaches also based on bodily neural activity for individuals living with epilepsy.

Biomarkers of attention bias during public speaking anxiety

The analysis of brain signals and their properties yields significant insights into the fundamental neural impairments associated with attention bias in individuals suffering from public speaking anxiety (PSA). This study aims to identify electroencephalogram (EEG) and performance biomarkers of attention bias in individuals with public speaking anxiety using the ex-Gaussian modeling technique, frontal alpha asymmetry (FAA) and delta-beta correlation (DBC). 12 subjects with high (H) PSA and 12 subjects with low (L) PSA performed the modified emotional stroop task. EEG data were captured using the low-cost 14-channel emotiv Epoc+. Results showed that the ex-Gaussian sigma was higher in the emotional condition in the high public speaking anxiety (HPSA) group, indicating attention bias. The study also found higher right FAA in HPSA compared to LPSA group. There was a negative correlation between σ and alpha power in the left region of the brain in the HPSA group, potentially related to attentional bias. Moreover, there was a notable trend towards significantly heightened DBC in the frontal and central regions of the brain among HPSA subjects. In conclusion, in biomedical engineering, the ex-Gaussian model, FAA and DBC are useful because they can identify EEG and performance biomarkers of attention bias in people with PSA.

Abnormal function of EPHA2/p.R957P mutant in congenital cataract.

To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity. A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited. Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals. Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery. The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software. Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2 (EPHA2). Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins. The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assay, respectively. The cell migration was analyzed by wound healing assay. Zebrafish model was generated by ectopic expression of human EPHA2/p.R957P mutant to demonstrate whether the mutant could cause lens opacity in vivo. A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif (SAM) domain of EPHA2. Functional studies demonstrated the variant's impact: reduced EPHA2 protein expression, altered subcellular localization, and disrupted interactions with other lens membrane proteins. This mutant notably enhanced human lens epithelial cell migration, and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human EPHA2/p.R957P mutant under differential interference contrast (DIC) optics. Novel pathogenic c.2870G>C variant of EPHA2 in a Chinese congenital cataract family contributes to disease pathogenesis.

Famine and Childhood: Ottoman Children’s Experiences during the Famine of 1873-1875

This article explores the unique experiences of children who lived in a famine-affected region of Central Anatolia between 1873 and 1875. The deplorable conditions forced some children to consume inappropriate foods, be traded for bread, be abandoned during migration, or be subjected to exploitation and domestic servitude. The article emphasizes the contrast between child-rearing practices and the concept of childhood in the Central Anatolian region and urban areas of the period. This challenges the prevailing emphasis in previous studies that have primarily examined urban children during the period of peace. Emphasizing the famine of 1873–1875, the research underscores that the concept of childhood and the material culture developed and adopted by urban families of the period under the effect of modernization were not observed in Central Anatolia. Thus, it is suggested that examining childhood in the Ottoman Empire necessitates a periodical and regional methodology that considers the socioeconomic and cultural variations that influenced the experiences of children in various regions and eras. In addition, the article delves into the Ottoman government’s response to the famine. The article addresses these issues by comprehensively examining Ottoman archival sources, periodicals and gazettes, together with contemporary accounts and reports from the famine period.

Chlorophyll a fluorescence and phytochemical response in blackberry species (Rubus sp) cultivated in the high tropics

BACKGROUND: The evaluation of chlorophyll fluorescence activity is a useful tool for rapid and effective assessments of the effect of abiotic factors on the physiology of different crops. In Rubus, this type of measurements describes tolerance to high temperatures, sensitivity to heat and morphological alterations in flowering and chlorophyll content, as a result of plant stress. OBJECTIVE: The present research estimated chlorophyll fluorescence and the presence of some phenolic compounds in the leaves of three cultivars of blackberry (Rubus sp.) established in the central region of Colombia, under conditions of open air between 2400 and 2800 masl. MATERIAL AND METHODS: This was done through the measurement of chlorophyll a (Junior-PAM II modulated fluorometer), the quantification of phenolic compounds (Folin Ciocalteu), the determination of antioxidant capacity (DPPH and ABTS) and the study of phenolic profiles (UHPLC) in leaves of three blackberry cultivars. RESULTS: Cultivars R. alutaceus (0.66), R. glaucus (0.73) and R. alpinus (0.76), presented values lower than the optimum (0.83), for the parameter Fv/Fm. In addition, the direct relationships between the parameters that define the behavior of PSII and the accumulation of different polyphenols were described. Reference was also made to the content of phenolic compounds (ranging from 125 to 150 mg GA g–1 dw), which did not show significant statistical differences. The heat map and principal component analysis show the close relationship between the parameters that characterize the functioning of PSII and the accumulation of phenolic compounds, as a mechanism of adaptation to the adverse conditions of the blackberry cultivars studied. CONCLUSIONS: The results reveal that the leaves of the Rubus studied could be a source of functional ingredients for use in the cosmetic, nutraceutical and food industries and epigallocatechin was attributed the greatest responsibility for the antioxidant capacity.

Temporal and spatial evolution simulation and attribution analysis of vegetation photosynthesis over the past 21 years based on satellite SIF data: a case study from Asia.

Photosynthesis in vegetation is one of the key processes in maintaining regional ecological balance and climate stability, and it is of significant importance for understanding the health of regional ecosystems and addressing climate change. Based on 2001-2021 Global OCO-2 Solar-Induced Fluorescence (GOSIF) dataset, this study analyzed spatiotemporal variations in Asian vegetation photosynthesis and its response to climate and human activities. Results show the following: (1) From 2001 to 2021, the overall photosynthetic activity of vegetation in the Asian region has shown an upward trend, exhibiting a stable distribution pattern with higher values in the eastern and southern regions and lower values in the central, western, and northern regions. In specific regions such as the Turgen Plateau in northwestern Kazakhstan, Cambodia, Laos, and northeastern Syria, photosynthesis significantly declined. (2) Meteorological factors influencing photosynthesis exhibit differences based on latitude and vertical zones. In low-latitude regions, temperature is the primary driver, while in mid-latitude areas, solar radiation and precipitation are crucial. High-latitude regions are primarily influenced by temperature, and high-altitude areas depend on precipitation and solar radiation. (3) Human activities (56.44%) have a slightly greater impact on the dynamics of Asian vegetation photosynthesis compared to climate change (43.56%). This research deepens our comprehension of the mechanisms behind the fluctuations in Asian vegetation photosynthesis, offering valuable perspectives for initiatives in environmental conservation, sustainability, and climate research.

Responsive feeding patterns during early childhood in urban areas. Argentina, 2018-2019.

Introduction. Dietary quality involves both the quantity and quality of food offered, the way and the setting in which it is offered, and the responses of the person offering it. The objective of this study was to identify behavioral patterns related to responsive feeding in children aged 6 to 23 months in urban areas from Argentina in 2018-2019. Population and methods. Secondary analysis based on data from the second National Survey on Nutrition and Health of 2018-2019 conducted in a multistage probability sample from urban areas of 5000 inhabitants or more in Argentina. A descriptive analysis and a principal component analysis were performed to identify responsive feeding patterns in 4379 children aged 6 to 23 months. Results. Five responsive feeding patterns were identified; the first 2 dimensions explained 71.1% of inertia (p = 0.013). The pattern with a prevailing possibility of experimentation, autonomy, interaction, and the absence of screens, rewards and distractions was associated with children older than 12 months from the central and south regions (Cuyo, Pampa, Greater Buenos Aires, and Patagonia), whereas the pattern related to a lower autonomy, experimentation, and self-regulation corresponded to children aged 6 to 11 months from the Northwest and Northeast regions. Conclusion. There is evidence of responsive feeding practices that correspond to distinguishable patterns, associated with different stages of life and with the region where the children live.

The geography of the craft beer scene in Budapest

PurposeThis paper aims to investigate the locational determinants of the craft beer industry in Budapest, Hungary, between 2009 and 2022.Design/methodology/approachThe authors use various count data models to determine the relationship between the number of microbreweries and locational factors.FindingsThe authors find that demand and supply-side factors, including income, unemployment, level of education, population density and the number of local businesses, affect the number of craft breweries. Whilst agglomeration effects proxied by breweries per capita in a district have a positive coefficient, the number of breweries in neighbouring districts is not significant. In addition, the authors do not observe any negative impact of COVID-19-related restrictions. The picture of a still-evolving, resilient craft beer sector emerges from our analysis.Originality/valueTo the best of the authors’ knowledge, this is one of the first specific studies on the craft beer sector in the Central and Eastern European region and the first to evaluate the location choices of craft breweries in Hungary within a municipality using an up-to-date data set. The authors’ analysis covers 14 years, from the early stages of craft brewery proliferation in Budapest until 2022, testing several hypotheses with respect to the location choices of these businesses.

Isoflurane-induced neuroinflammation and NKCC1/KCC2 dysregulation result in long-term cognitive disorder in neonatal mice

BackgroundThe inhalational anesthetic isoflurane is commonly utilized in clinical practice, particularly in the field of pediatric anesthesia. Research has demonstrated its capacity to induce neuroinflammation and long-term behavioral disorders; however, the underlying mechanism remains unclear [1]. The cation-chloride cotransporters Na+–K+–2Cl−–1 (NKCC1) and K+–2Cl−–2 (KCC2) play a pivotal role in regulating neuronal responses to gamma-aminobutyric acid (GABA) [2]. Imbalances in NKCC1/KCC2 can disrupt GABA neurotransmission, potentially leading to neural circuit hyperexcitability and reduced inhibition following neonatal exposure to anesthesia [3]. Therefore, this study postulates that anesthetics have the potential to dysregulate NKCC1 and/or KCC2 during brain development.MethodsWe administered 1.5% isoflurane anesthesia to neonatal rats for a duration of 4 h at postnatal day 7 (PND7). Anxiety levels were assessed using the open field test at PND28, while cognitive function was evaluated using the Morris water maze test between PND31 and PND34. Protein levels of NKCC1, KCC2, BDNF, and phosphorylated ERK (P-ERK) in the hippocampus were measured through Western blotting analysis. Pro-inflammatory cytokines IL-1β, IL-6, and TNF-α were quantified using ELISA.ResultsWe observed a decrease in locomotion trajectories within the central region and a significantly shorter total distance in the ISO group compared to CON pups, indicating that isoflurane induces anxiety-like behavior. In the Morris water maze (MWM) test, rats exposed to isoflurane exhibited prolonged escape latency onto the platform. Additionally, isoflurane administration resulted in reduced time spent crossing in the MWM experiment at PND34, suggesting long-term impairment of memory function. Furthermore, we found that isoflurane triggered activation of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α; downregulated KCC2/BDNF/P-ERK expression; and increased the NKCC1/KCC2 ratio in the hippocampus of PND7 rats. Bumetadine (NKCC1 specific inhibitors) reversed cognitive damage and effective disorder induced by isoflurane in neonatal rats by inhibiting TNF-α activation, normalizing IL-6 and IL-1β levels, restoring KCC2 expression levels as well as BDNF and ERK signaling pathways. Based on these findings, it can be speculated that BDNF, P-ERK, IL-1β, IL-6 and TNF - α may act downstream of the NKCC1/KCC2 pathway.ConclusionsOur findings provide evidence that isoflurane administration in neonatal rats leads to persistent cognitive deficits through dysregulation of the Cation-Chloride Cotransporters NKCC1 and KCC2, BDNF, p-ERK proteins, as well as neuroinflammatory processes.

Groundwater quality appraisal and zone mapping for agriculture utilities in Wadi Fatima, Saudi Arabia using water quality indices, boron and trace metals.

Groundwater quality in Wadi Fatimah is evaluated and demarcated for agriculture utilities using comprehensive approaches namely, international standards, agricultural water quality (AWQ) indices, irrigation water quality index (IWQI), and trace metals. Groundwater samples were collected (n = 59) and analysed for EC, pH, major and minor ions and trace metals. According to FAO recommendations, 42% of samples (EC > 3000 µS/cm) are inappropriate for agricultural uses. AWQ indices including salinity hazard, Kelly's ratio and Na% show that 50%, 19% and 37% of samples, respectively, are unsuitable for agricultural uses. USSL classification reveals that groundwater is preferable only for high-permeability soils and salt-tolerant crops. IWQI suggests that 88% of samples are moderately usable for agriculture. The interrelationship between water salinity and crop yield justified that 73%, 59%, 51% and 25% of samples are desirable to yield 90% in date palm trees, sorghum, rice and citrus fruits, respectively. Groundwater is appropriate for date palm trees except in downstream regions. Boron concentration suggests that 52%, 81% and 92% of samples are suitable for sensitive, semi-tolerant and tolerant crops, respectively. Groundwater in the central part (suitable for sensitive crops), central and upstream regions (semi-tolerant crops) and all regions except downstream (tolerant crops) are suitable for cultivation. Trace metals contents illustrate that 36%, 34%, 22%, 8%, 5% and 100% of samples are inappropriate for agriculture due to high concentrations of Cr, Cu, Ni, V, Mn and Mo, respectively in the groundwater. Further, AWQ indices, IWQI, USSL classifications and trace metals ensure that groundwater in the downstream, and a few pockets in the upstream are unfit for agricultural uses. This study recommends that groundwater in this basin is more suitable for tolerant crops (ie. date palm, sorghum) followed by semi-tolerant and sensitive crops.

Buffel Grass (Pennisetum ciliare) Ecotypes Suitable for Subtropical Livestock in the North Central Region of Mexico

The objective was to determine the forage production and nutritional quality of six buffel grass ecotypes in vegetative and physiological maturity stages. The experiment was carried out at the Los Cañones Experimental Station in Zacatecas, Mexico. The ecotypes were as follows: E-42, E-45, E-66, E-72, E-S245, and the Titan variety as a control. The experiment design was a completely randomized block with three replications, and the evaluation years were from 2020 to 2022. The variables measured were as follows: plant height (PH), dry matter yield (DMY), leaf (Lf) and stem-inflorescence (St), crude protein (CP), neutral (NDF), and acid detergent fiber (ADF). Pearson’s correlation and a combined analysis of variance were performed for each growth stage. A correlation analysis showed significant relationships (p < 0.05) between variables. In the vegetative stage, ecotypes E-42, E-45, and E-S45 showed accumulations of over 12% of CP, which were higher (p < 0.05) than the ones for Titan. Low values of E-S245 (p < 0.05) for NDF (63.44%) and ADF (44.49%) stood out among all ecotypes. In the maturity stage, Titan was surpassed by E-45 and E-S245 with CP higher than 4%. The neutral and acid fibers in E-42, E-45, and E-S245 were less than in Titan (p < 0.05). Ecotypes E-42 and E-S245 are alternatives to improve feed efficiency in the dry subtropical climate of Zacatecas.

How to drive sustainable economic development: The role of fintech, natural resources, and social vulnerability

The advancement of digital technology, the deepening of economic globalization, and the escalating geopolitical tensions have heightened the focus of policymakers and researchers on fostering sustainable economic development. Employing an analytical framework of "DrivingForce-State-Response," this study aims to investigate the impact of fintech, natural resources, and social vulnerability on sustainable economic development. Utilizing the AHP and TOPSIS models alongside cross-sectional data from the 31 provinces of mainland China in 2022, the research reveals that the eastern region exhibits the highest level of sustainable economic development, trailed by the central region, with the western region lagging behind. Notably, capital input in financial technology, the natural resource conversion rate, and social resilience emerge as pivotal factors driving sustainable economic progress across the three dimensions.These may include initiatives to enhance capital investment in fintech, optimize resource conversion practices, and bolster social resilience through targeted interventions such as healthcare, education, and social assistance programs. Additionally, fostering collaboration and knowledge-sharing among regions could help mitigate disparities and promote inclusive growth across the mainland.

Prevalence of Osteoporosis and Its Effect on Residual Ridge Resorption in Postmenopausal Females of Rural Central Indian Region

Prevalence of Osteoporosis and Its Effect on Residual Ridge Resorption in Postmenopausal Females of Rural Central Indian Region

Research on Territorial Spatial Development Non-Equilibrium and Temporal–Spatial Patterns from a Conjugate Perspective: Evidence from Chinese Provincial Panel Data

Clarifying the intrinsic nature and formation mechanisms of the territorial spatial development non-equilibrium, optimizing the allocation of territorial resources, promoting regional balanced development, and alleviating regional development disparities have become common endeavors of all countries seeking to enhance development quality. This study, based on the land use and socio-economic data of 31 provinces and cities in China from 2006 to 2020, utilized the kernel density estimation method and ArcGIS spatial analysis to explore the spatiotemporal evolution characteristics of China’s territorial spatial development non-equilibrium. The research findings are as follows: (1) From 2006 to 2020, both the land development intensity and land supply capacity showed an increasing trend, with increases of 21.4% and 8.03%, respectively. However, their spatiotemporal evolutions significantly differed. (2) The state of the territorial spatial development non-equilibrium in China significantly improved, with a rising trend in the territorial spatial equilibrium degree. Regional disparities in the territorial spatial equilibrium degree decreased. The number of provinces and cities in a state of underdevelopment decreased from 23 to 8, while the number in an equilibrium state increased from 7 to 21. The central and western regions showed more significant improvements in the territorial spatial equilibrium degree and a greater reduction in regional disparity when compared to the eastern and northeastern regions. (3) China exhibited distinct regional disparities in the territorial spatial equilibrium degree. The overdeveloped areas were Beijing and Shanghai. The underdeveloped regions were primarily concentrated in western areas, including Sichuan, Yunnan, and Xinjiang. The high-level equilibrium regions were predominantly located in the southeastern coastal provinces and the central plains region, while the low-level equilibrium regions included Inner Mongolia, Ningxia, Qinghai, and the three northeastern provinces. (4) From the perspective of the number of agglomeration types, the order is HH (high–high) > LH (low–high) > LL (low–low) > HL (high–low), and China’s TSED exhibits a spatial proximity peer effect. The innovation of this study consists of the following aspects: (1) The clarification of the fact that the essence of equilibrium does not require an exact 1:1 match, as with “two horses”; rather, it entails the maintenance of a slight surplus of land supply capacity over land development intensity. This approach allows the possibility of future sustainable development by leaving room for expansion. (2) The differentiation between high-intensity conjugation (in terms of both quantity and quality) and low-intensity conjugation (quantity only) from a conjugate perspective. This categorization aids in a more comprehensive and in-depth understanding of the territorial spatial development non-equilibrium and its spatiotemporal patterns. It provides crucial information for the formulation of sustainable national territorial development plans and the promotion of a regional development equilibrium.

A era da ebulição global: desafios e oportunidades para a resiliência climática na região centro-americana

[Introduction]: In July 2023 was announced the end of planetary warming and the beginning of the era of the global boiling. A climatic anomaly whose unprecedented, aggressiveness will hit the Central American region. [Methodology]: Through technological surveillance tools and data analytics, this study shows a series of challenges and opportunities to meet this threat and move towards resilient regional performance. [Results]: All countries have signed agreements and declaratory public policies for the climate resilience, however historical failures persist as well environmental passives to reduce greenhouse gas emissions and the strong dependence for the use of fossil energy. In contrast, Central America enjoys a matrix of opportunities to increase the climatic ambition, also a diverse mix of renewable energy sources, environmental pay mechanisms and actions to impulse circular economy and the bioeconomy [Conclusions]: The regional agenda fail in connect to a climate shielding to respond the rigors of the boiling era. Regarding those balances, and the scientific evidence, a road map, with climate smart and socially inclusive actions, is proposed. [Recommendations]: For the monitoring, research, and education programs on the boiling era, a regional observatory, on climate resilience (OR2C), is recommended.

Investigating the relationship between globalization and economic growth in EECA countries: The mediating role of governance

Globalisation has been on an upward trend since the 1980s, consequentially ushering in growth and development benefits that has transformed the welfare standings of many countries worldwide. The Eastern Europe and Central Asia region, particularly, cannot be isolated from globalisation gains. However, the region has currently been typified with the on-going Russo-Ukraine war. Given that EECA economies are intertwined to that of Russia and Ukraine, this paper seeks to investigate the relationship between globalisation and economic growth in EECA countries within the framework of the mediating role of governance. The results revealed that overall, globalization and its economic, social, and political dimensions do not affect economic growth in EECA countries. The article also established that governance does not mediate the impact of globalization and its dimensions on economic growth in EECA. Similarly, governance dimensions were found to have an insignificant effect in mediating the impact of overall globalization on economic growth in EECA. However, fixed capital formation was found to significantly affect economic growth in EECA even though the power of its effect is relatively low. Irrespective, globalization may potentially be valuable in stimulating trade, investments, and scientific advancements that are regarded as the foundations of contemporary growth and development.

Research on Environmental Performance Measurement and Influencing Factors of Key Cities in China Based on Super-Efficiency SBM-Tobit Model

In recent years, China has experienced significant economic growth and some degree of environmental pollution control. However, achieving a perfect balance between the environment and economic development remains a challenge. In order to seek solutions to this issue and promote the sustainable development of cities, this paper starts from the urban level, which is relatively lacking in existing research. Based on the panel data of urban indicators from 2013 to 2021, it quantifies the environmental performance of key cities using the slack-based measure (SBM) model of super-efficiency based on a non-expected output. Furthermore, it utilizes the Tobit panel regression model suitable for limited dependent variables to analyze the impact of driving factors on the environmental performance of key cities, and it further explores the reasons for the loss of urban environmental performance from the dual perspectives of inputs and outputs. The research findings indicate the following. (1) The average environmental performance of 30 key cities has shown an increasing trend but has not yet reached a valid state. The cities’ environmental performance rises in the range of [0.444, 0.821], indicating that there is room for improvement in urban environmental management. (2) Cities in the northeastern region of China have lagged behind the eastern, central, and western regions in terms of environmental performance over this nine-year period, and the redundancy of undesirable outputs is partly responsible for this decline. (3) The large proportion of the secondary industry, the number of vehicles on the road, and the population density have a significantly negative impact on urban environmental performance, while the per capita regional GDP and urban maintenance and construction funds make a positive difference. These research findings provide a scientific basis and valuable insights into urban environment performance enhancement and can serve as a reference for areas in need of balanced development between the urban environment and economic growth.

Spatial inequality in the accessibility of healthcare services in the Philippines

Ensuring equitable access to healthcare is important for universal health coverage (UHC). Using the enhanced two-step floating catchment area (E2SFCA) method, we found disparities in the spatial accessibility of outpatient and inpatient healthcare facilities in the Philippines, particularly in the central and southern regions of the country. Municipalities with a higher proportion of older people had better spatial accessibility to outpatient care, while municipalities with a higher density of older people had better accessibility to inpatient care. Municipalities with high poverty rates had better accessibility to outpatient care but poorer accessibility to inpatient care. Addressing these disparities is essential for achieving UHC in the Philippines.

Analysis of dynamic relationship between agricultural products circulation service industry and circulation efficiency in less developed regions: based on data from Western China

The market circulation system for agricultural products in less-developed regions lags behind; it fails to meet the requirements for efficient circulation. Therefore, it is crucial to explore the dynamic relationship between the Agricultural Products Circulation (APC) service industry and circulation efficiency. Using panel data from 29 regions in China, the entropy method measured the Development Level (DL) of the APC service industry, while the non-oriented super-efficiency Slacks-Based Measure (SBM) model was employed to assess the APC efficiency. A Panel Vector Autoregressive (PVAR) model was built for estimation. The impulse response function and variance decomposition were utilized to analyze the differences in the DL of the APC service industry, circulation efficiency, and their interaction mechanism across the Western, Central, and Eastern regions of China. The findings indicate that the DL of the APC service industry and APC efficiency in the less-developed regions of the West have a positive driving effect on each other. However, the magnitude of this effect was asymmetric and transient. The APC service industry’s DL and APC efficiency are more dependent on their inertia, and no efficient two-way feedback mechanism has been formed. This study provides a reference for the construction and sustainable development of modernized APC systems in less-developed regions.

Bactericidal effectors of the Stenotrophomonas maltophilia type IV secretion system: functional definition of the nuclease TfdA and structural determination of TfcB.

Stenotrophomonas maltophilia expresses a type IV protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria and does so partly by secreting the effector TfcB. Here, we report the structure of TfcB, comprising an N-terminal domain similar to the catalytic domain of glycosyl hydrolase (GH-19) chitinases and a C-terminal domain for recognition and translocation by the T4SS. Utilizing a two-hybrid assay to measure effector interactions with the T4SS coupling protein VirD4, we documented the existence of five more T4SS substrates. One of these was protein 20845, an annotated nuclease. A S. maltophilia mutant lacking the gene for 20845 was impaired for killing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Moreover, the cloned 20845 gene conferred robust toxicity, with the recombinant E. coli being rescued when 20845 was co-expressed with its cognate immunity protein. The 20845 effector was an 899 amino-acid protein, comprised of a GHH-nuclease domain in its N-terminus, a large central region of indeterminant function, and a C-terminus for secretion. Engineered variants of the 20845 gene that had mutations in the predicted catalytic site did not impede E. coli, indicating that the antibacterial effect of 20845 involves its nuclease activity. Using flow cytometry with DNA staining, we determined that 20845, but not its mutant variants, confers a loss in DNA content of target bacteria. Database searches revealed that uncharacterized homologs of 20845 occur within a range of bacteria. These data indicate that the S. maltophilia T4SS promotes interbacterial competition through the action of multiple toxic effectors, including a potent, novel DNase.IMPORTANCEStenotrophomonas maltophilia is a multi-drug-resistant, Gram-negative bacterium that is an emerging pathogen of humans. Patients with cystic fibrosis are particularly susceptible to S. maltophilia infection. In hospital water systems and various types of infections, S. maltophilia co-exists with other bacteria, including other pathogens such as Pseudomonas aeruginosa. We previously demonstrated that S. maltophilia has a functional VirB/D4 type VI protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria. Since most work on antibacterial systems involves the type VI secretion system, this observation remains noteworthy. Moreover, S. maltophilia currently stands alone as a model for a human pathogen expressing an antibacterial T4SS. Using biochemical, genetic, and cell biological approaches, we now report both the discovery of a novel antibacterial nuclease (TfdA) and the first structural determination of a bactericidal T4SS effector (TfcB).