Positive Nonlinear Relationship Research Articles

Association of the systemic immune-inflammation index with all-cause and cardiovascular mortality in individuals with rheumatoid arthritis

The systemic immune-inflammation index (SII), a metric reflecting systemic inflammatory response and immune activation, remains underexplored concerning its correlation with mortality among rheumatoid arthritis (RA) patients. This study aimed to delineate the association between SII and both all-cause and cardiovascular mortality within the cohort of American adults diagnosed with RA, utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 1999 to 2018. The investigation extracted data from NHANES cycles between 1999 and 2018, identifying RA patients through questionnaire responses. The SII was computed based on complete blood counts, employing the formula: (platelets × neutrophils) / lymphocytes. The optimal SII cutoff value for significant survival outcomes was determined using maximally selected rank statistics. Multivariable Cox proportional hazards models assessed the relationship between SII levels and mortality (all-cause and cardiovascular) among RA patients, with subgroup analyses examining potential modifications by clinical confounders. Additionally, restricted cubic spline (RCS) analyses were conducted to explore the linearity of the SII-mortality association. The study encompassed 2070 American adults with RA, among whom 287 exhibited a higher SII (≥ 919.75) and 1783 a lower SII (< 919.75). Over a median follow-up duration of 108 months, 602 participants died. After adjustments for demographic, socioeconomic, and lifestyle variables, a higher SII was associated with a 1.48-fold increased risk of all-cause mortality (hazard ratio [HR] = 1.48, 95% confidence interval [CI] 1.21–1.81, P < 0.001) and a 1.51-fold increased risk of cardiovascular mortality (HR = 1.51, 95% CI 1.04–2.18, P = 0.030) compared to a lower SII. Kaplan–Meier analyses corroborated significantly reduced survival rates within the higher SII cohort for both all-cause and cardiovascular mortality (Pall-cause mortality < 0.0001 and Pcardiovascular mortality = 0.0004). RCS analyses confirmed a positive nonlinear relationship between SII and mortality rates. In conclusion, the SII offers a straightforward indicator of the equilibrium between detrimental innate inflammation and beneficial adaptive immunity. Our investigation, utilizing a comprehensive and nationally representative sample, reveals that elevated SII levels independently forecast a greater risk of mortality from all causes, as well as cardiovascular-specific mortality, in individuals suffering from RA. These insights underscore the clinical relevance of the SII as an affordable and readily accessible biomarker. Its incorporation into regular clinical practice could significantly enhance the precision of risk assessment and forecasting for patients with RA, facilitating more tailored and effective management strategies. Specifically, patients with high SII levels could be identified for more stringent cardiovascular risk management, including closer monitoring, lifestyle interventions, and aggressive pharmacological treatments to mitigate their increased risk of mortality.

J-shaped association of the triglyceride glucose-body mass index with new-onset diabetes

The triglyceride glucose-body mass index (TyG-BMI) is a convenient and clinically significant indicator of insulin resistance. This study aims to investigate the correlation between TyG-BMI and the onset of new-onset diabetes and determine an optimal reflection point for TyG-BMI. An analysis was conducted on 1917 participants from the risk evaluation of cancers in Chinese diabetic individuals: a lONgitudinal (REACTION) study. Participants were categorized based on their TyG-BMI, and the relationship between TyG-BMI and the incidence of new-onset diabetes was explored through logistic regression models, smoothed curve fitting with restricted cubic spline, and a two-piecewise logistic regression model. The mean age of the participants was 57.60 ± 8.89 years, with 66.5% being females. The mean TyG-BMI was 223.3 ± 32.8. Ultimately, 137 individuals (7.1%) progressed to diabetes after three years. After adjusting for covariates, TyG-BMI exhibited a positive correlation with new-onset diabetes (odd ratios (OR) for each standard deviation increase = 1.330, 95% CI 1.110–1.595). The relationship between TyG-BMI and new-onset diabetes was non-linear, with a inflcetion point at 202.9. This study reveals a positive non-linear relationship between TyG-BMI and the risk of new-onset diabetes in Chinese middle-aged and elderly individuals. When TyG-BMI exceeds 202.9, there is a significantly heightened risk of new-onset diabetes. These findings offer valuable insights for preventing new-onset diabetes.

Association of systemic inflammation response index with mortality risk in older patients with hip fracture: a 10-year retrospective cohort study.

With a rapidly aging global population, the assessment of mortality risk following hip fracture in older adults has received increasing attention. Recently, the system inflammation response index (SIRI) has been identified as a novel prognostic marker to reflect both systemic inflammation and immune status. However, it is not yet known whether SIRI is a potential predictor of subsequent death in hip fracture patients. Therefore, this study aimed to investigate the association between SIRI and mortality in older patients with hip fracture. A total of 1,206 older hip fracture patients undergoing surgery between January 2013 and December 2022 were consecutively derived from our longitudinal database. Patients were divided into three groups according to SIRI tertiles, calculated as neutrophil × monocyte / lymphocyte. Survival status was obtained from medical records or telephone interviews, and the study outcome was all-cause mortality after hip fracture at the longest follow-up. Multivariate Cox proportional hazard model and restricted cubic spline (RCS) regression model were used to evaluate the association between SIRI and mortality. Moreover, a series of sensitivity analyses were conducted to further validate the robustness of the association. During a median follow-up of 43.85 months, 337 patients (27.94%) died. After full adjustment, each unit increase in SIRI was significantly associated with a 2.2% increase in overall mortality (95% confidence interval [CI]: 1.001-1.042, p = 0.029). Similarly, compared with the first tertile of SIRI, the second and third tertile showed a 1.335-fold (95% CI: 1.011-1.762, p = 0.042) and 1.447-fold (95% CI, 1.093-1.917, p = 0.010) higher risk of death. Sensitivity analyses confirmed the stability of the association. Moreover, RCS analysis revealed a positive non-linear relationship between SIRI and mortality (P for nonlinearity = 0.021). High SIRI level at admission was significantly and positively associated with an increased risk of death, suggesting that SIRI may be an independent predictor of mortality in older patients with hip fracture.

Unprecedented Human‐Perceived Heat Stress in 2021 Summer Over Western North America: Increasing Intensity and Frequency in a Warming Climate

AbstractThe unprecedented 2021 June‐July heatwave in Western North America resulted in record‐breaking human‐perceived heat stress across the region, measured by the humidex considering both air temperature and humidity. During extended summer (June‐September), both 95th percentiles of daily maximum humidex (HX95) and air temperature (TX95) have increased over the 1940–2022 period, with even faster intensification in the last two decades (2001–2022). HX95 has increased more than TX95 because of the positive monotonic nonlinear relationship between humidex and air temperature at a given level of relative humidity. The Canadian Earth System Model version 5 (CanESM5) projects a larger increase in human‐perceived heat stress than air temperature across the region under low to high emission scenarios (HX95 increases 4.40–7.04°C and TX95 increases 2.92–4.65°C between 1981–2010 and 2041–2060). Moreover, CanESM5 projects significant increases in the frequency of HX and TX conditions that exceed the levels reached in 2021 under intermediate and high emission scenarios.

The role of socioeconomic status and oxidative balance score in erectile dysfunction: A cross-sectional study

BackgroundErectile dysfunction (ED) is a complex disorder of biopsychosocial etiology. Approximately 3%–77 % of adult men worldwide are more or less affected by ED. ObjectiveThis cross-sectional study investigated the association between ED and socioeconomic status (SES) based on a nationally representative adult male population. MethodsThe poverty income ratio (PIR), which refers to household income ratio to the established poverty line, was used to assess SES. Oxidative stress related to diet and lifestyle was reflected by oxidative balance score (OBS). Erectile function was evaluated using a questionnaire. Based on the results of the questionnaire, participants were divided into two groups of those without ED (always or almost always be able to erect and keep erection, usually be able to erect and keep erection) and with ED (sometimes be able to erect and keep erection, never be able to erect and keep erection). Multivariate logistic regression, multiple models, and restricted cubic spline (RCS) were used to analyze and describe the interaction between ED, OBS, and SES. ResultsCompared with men without ED, those with ED were more likely to be older in age (43.98 vs 37.74, P＜0.0001), and less educated (P < 0.001), and with a ratio of family income to poverty less than 3.5 (P = 0.02), higher BMI (30.11 vs 27.84, P＜0.0001), lower OBS (21.71 vs 23.17, P = 0.04), having habit of smoking (P = 0.04), with diabetes (P＜0.0001), and with hypertension (P = 0.003). Participants with higher PIR were more likely to report good erectile function than those with lower PIR through multivariate analysis (OR = 0.49, 95 % CI = 0.31–0.78, P = 0.005). The RCS model revealed a negative non-linear correlation of PIR with ED when PIR ≤3.89. It is interesting to note that PIR was＞3.89 showed a positive non-linear relationship with ED. ConclusionThe social determinants of health and intake of oxidants and antioxidants were considered as risk factors for ED and could be studied as a research focus in the future.

Higher waist circumference is associated with increased likelihood of female infertility: NHANES 2017-2020 results.

Waist circumference can be used as an anthropometric measure to assess central obesity and is easier and more convenient than the waist-to-hip ratio in identifying the risk of obesity and medical problems. Most studies showing an association between obesity and infertility in women have used BMI to measure obesity. Our goal was to examine any potential association between waist circumference and infertility. This cross-sectional study, which formed part of the National Health and Nutrition Examination Survey (NHANES), comprised women ages 18 to 45 between 2017 and 2020. Participants without waist circumference data or information on infertility were removed from the study. The independent relationship between waist circumference and infertility was investigated using weighted binary logistic regression and subgroup analysis. We investigated 1509 participants and discovered that the prevalence of infertility rose as the WC trisection rose. (tertile 1, 7.55%; tertile 2, 10.56%; tertile 3, 15.28%; trend < 0.001). Multivariate logistic regression showed that after total adjustment, higher WC levels were associated with an increased likelihood of infertility in women (OR1.02; 95% CI 1.01-1.03), and There was a 2% rise in the incidence of infertility for every unit (cm) increased WC. Subgroup analysis and interaction tests showed no significant dependence of the effects of marital status, diabetes, hypertension, and high cholesterol on the association between WC and infertility (p for all interaction tests > 0.05). The inflection point of the positive non-linear relationship between WC and infertility was 116.6 cm. Excessive waist circumference assessment may increase the probability of infertility, and more attention should be paid to the management of waist circumference should be given more attention.

How does the digital transformation of corporates affect green technology innovation? An empirical study from the perspective of asymmetric effects and structural breakpoints

With the continuous advancement of the digital economy and green development strategies, exploring the impact of digital transformation on corporate green technology innovation becomes an importantly urgent issue. Based on the perspectives of asymmetric effects and structural breakpoints, this paper empirically analyses the effect of digital transformation on green technology innovation, as well as its heterogeneity and non-linear characteristics, using fixed effect models and panel threshold model with a sample of Chinese A-share-listed corporates from 2011 to 2021. The findings suggest that digital transformation of corporates can significantly promotes green technology innovation, which remains valid after a series of endogenous and robustness tests. Heterogeneous regression results shows that digital transformation exhibits an asymmetric impact on green technology innovation, with greater incentive effect for state-owned corporates, manufacturing corporates, and corporates located in areas with stricter environmental regulations. Additionally, threshold effect analyses prove that a positive non-linear relationship between digital transformation and green technology innovation, when corporate human capital, industry competition and regional institutional quality exceeded their respective structural breakpoints, the marginal contribution of digital transformation is further strengthened. This research provides clearer policy insights for corporates to promote cleaner production and low carbon development through digitization.

How doctor image features engage health science short video viewers? Investigating the age and gender bias

PurposeShort-form health science videos have become an important medium for disseminating health knowledge and improving public health literacy. However, the factors that determine viewer engagement are not well understood. This study aims to address this research gap by investigating the association between doctor image features and viewer engagement behavior, building on the personal branding theory and information signaling theory.Design/methodology/approachA sample of 1245 health science short-form videos was collected, and key video features related to doctor images were extracted through manual labeling. Multi-variable regression analysis and SPSS process model were employed to test the hypotheses.FindingsThe results show that doctor image features are significantly associated with viewer engagement behavior. Videos featuring doctors in medical uniforms receive more viewer likes, comments and shares. Highlighting the doctor's title can increase viewer collections. Videos shot in a home, white wall, or study room setting receive more like, comments and sharing. The doctor's appearance demonstrates a positive nonlinear relationship with viewer likes and comments. Young doctors with title information tend to attract more video collections than older doctors with title information. The positive effect of the doctor's appearance and showing title information, become more significant among male doctors.Originality/valueThis research provides novel insights into the factors that determine viewer engagement behavior in short-form health science videos. Specific doctor image features can enhance viewer engagement by signaling doctor professionalism. The results also suggest that there may be age and gender biases in viewers' perceptions.

Association between weight-adjusted-waist index and female infertility: a population-based study.

Obesity is detrimental to infertility. The association between weight-adjusted-waist index (WWI, a recently developed adiposity indicator) and infertility has not previously been confirmed. The data for this study were obtained from the National Health and Nutrition Examination Survey (NHANES) 2013-2018. Each participant's WWI was calculated as their waist circumference in centimeters by the square root of weight in kilograms. Multivariable logistic regression and generalized additive model were utilized to investigate the relationship between WWI with infertility. We used smoothed curve fitting to explore the non-linear relationship. Subgroup analysis and interaction tests were also conducted. A total of 3,526 participants with ages from18 to 45 were enrolled, 364 of whom were infertile. With the higher WWI, infertility was more prevalent (OR = 1.42, 95% CI: 1.22-1.65), and this association was still consistent in subgroups (all P for interaction> 0.05). Smoothed curve fitting showed a positive non-linear relationship between WWI and infertility. Furthermore, we discovered that WWI had a stronger connection with the risk of infertility than other markers of obesity including WC, body mass index (BMI) and a body shape index (ABSI). Weight-adjusted-waist index levels were positively linked to an increased risk of infertility in American females and showed a stronger association than other markers of obesity. Our research indicated WWI could help identify women with infertility, and managing obesity as determined by WWI may help to reduce the risk of infertility.

Association Between Chinese Visceral Adipose Index and Albuminuria in Chinese Adults: A Cross-Sectional Study.

To explore the correlation between Chinese visceral adipose index (CVAI) and urinary microalbumin/creatinine ratio (UACR) and urinary albumin, and whether there is any difference in correlation between Han and Tujia ethnicity. This cross-sectional study was conducted in Changde, Hunan, China from May 2021 to December 2021. Biochemical indicators including anthropometric parameters, blood pressure, blood glucose, blood lipids, and UACR of the participants were measured. Univariate analysis, multivariate analyses and multinomial logistic regression analysis were carried out to assess the association between CVAI and albuminuria. In addition, curve fitting and threshold effect analysis were used to explore the nonlinear association between CVAI and albuminuria, and to observe whether there were ethnic differences in this association. A total of 2026 adult residents were enrolled in this study, 500 of whom had albuminuria. Population-standardized prevalence of albuminuria is 19.06%. In the multivariable model adjusted for confounding factors, the odds ratio (OR) of albuminuria for pre-unit increase of CVAI and pre-SD increase of CVAI were 1.007 (1.003-1.010) and 1.298 (1.127-1.496), respectively. Multinomial logistic regression analysis confirmed the robustness and consistency of the results.The generalized additive model showed that CVAI and albuminuria had a nonlinear relationship with inflection point at 97.201 using the threshold effect. Compared with Han ethnic groups, the threshold between CVAI and albuminuria in Tujia people moved backward. The thresholds were 159.785 and 98.527, respectively. There was a positive nonlinear dose-response relationship between increased CVAI and higher levels of albuminuria. Maintaining appropriate CVAI levels may be important for the prevention of albuminuria.

Does environmental regulation narrow the north-south economic gap ? - Empirical evidence based on panel data of 285 prefecture-level cities

The economic differentiation between the north and the south of China, as a long-standing phenomenon of unbalanced regional economic development, is aggravating, and has gradually become a resistance to the construction of a new development pattern and regional coordinated development. Most of the existing studies focus on the comparison of differences between the Eastern, Central and Western regions of China, but there is little discussion on the economic gap between China's North-South economy. In addition, through the literature review, no attention has been paid to the environmental regulation factor that leads to the economic gap between the North and the South. In view of this, the study constructs a benchmark regression model and a non-linear regression model based on the balanced panel data of 285 cities in China from 2004 to 2019, explores the role that environmental regulation plays in the widening of China's North-South economy gap. The results show that, firstly, environmental regulation is significantly conducive to narrowing the economic gap between the North and the South; In addition, with the greater intensity of environmental regulation, the economic gap shows a trend of “narrowing first, expanding then”, that is, There exists positive U-shaped nonlinear relationship between them. Finally, the heterogeneity of urban scale leads to significant differences in the position and shape of the positive U-shaped curve, which exists between environmental regulation and China's North-South economy gap. The test results shows that the inflection point level of the U-shaped curve in the North is higher than that in the South. Based on this, the study proposes to adjust environmental policies accordingly under regional differentiated conditions, increase financial investment in improving environmental regulation tools and promote coordinated environmental governance in the North and South regions, to promote regional coordinated and sustainable development, provide empirical evidence and theoretical reference to improve people's livelihood and well-being and ultimately achieve the goal of common prosperity.

A View of Industrial Agglomeration, Air Pollution and Economic Sustainability from Spatial Econometric Analysis of 273 Cities in China

Industrial agglomeration in a region changes the economic structure, strategic layout and resource status of a city, and has an important impact on sustainable economic development. The relationship between industrial agglomeration, air pollution and economic sustainability is a key issue concerning the high-quality development of national economy. China is a developing country that once experienced severe air pollution. Now, the Chinese government is aiming to achieve the goal of sustainable and high-quality economic development in China. In this paper, a spatial Dubin model was developed to study the relationship between industry, environment and the economy. The statistical analysis used the air pollutant data of 273 prefecture-level cities in China from 2015 to 2018. The results showed that: (1) there was a positive U-shaped nonlinear relationship between industrial agglomeration and sustainable economic development, and there was a spatial spillover effect. (2) There was a positive U-shaped nonlinear relationship between air pollution and sustainable economic development, and there was a spatial spillover effect between them. (3) The effect of industrial agglomeration on sustainable economic development was influenced by air pollution, an intermediary variable. The existence of air pollution weakens the promoting effect of industrial agglomeration on sustainable economic development.

The effect of digital transformation on real economy enterprises’ total factor productivity

The digital transformation of real economy enterprises is essential for optimizing resource allocation, improving operation efficiency, and realizing high-quality innovation and development. Using the data of listed companies from 2007 to 2020, this study empirically explores the impact mechanism of the advancement of real economy enterprises' digital transformation on total factor productivity (TFP). The results reveal a positive nonlinear U-shaped relationship, demonstrating that real economy enterprises' TFP is reduced at the initial stage of digital transformation, then improves after exceeding a critical threshold value. Real economy enterprises' digital transformation impacts TFP through working capital turnover rate, human capital structure, and financing constraints. The heterogeneity analysis results indicate that the impact of advancing real economy enterprises' digital transformation on TFP is not affected by the size of enterprises' assets or enterprises' ownership. The research results provide direct evidence of the effect of real economy enterprises’ digital transformation on TFP at the microlevel, providing policy insights for the high-quality development of real economy enterprises.

Strengthening of surface urban heat island effect driven primarily by urban size under rapid urbanization: national evidence from China

ABSTRACT Surface urban heat islands (SUHIs) have received worldwide attention owing to their significant adverse impacts on socio-economic and environmental conditions. However, how the SUHIs vary across cities of different sizes and whether there is a threshold for city size that affect SUHIs were not explicit due to the limited selection of large cities in previous studies. Our study attempts to support comprehensive decision-making for national sustainable spatial management of SUHI in urbanized areas of different sizes. We used impervious surface area data to define the urbanized boundary for obtaining the SUHI in China. Then we analyzed the spatio-temporal patterns of SUHIs under China’s rapid urbanization. We furtherly constructed spatial autoregressive and structural equation models to verify the drivers’ direct and indirect contributions to SUHI. The SUHI effects existed extensively in most urbanized areas, not only in large or mega urbanized areas (average value: 2.08 ± 0.68°C) but also in petty urbanized areas (average value: 0.64 ± 0.19°C). We also found that the size of urbanized areas contributed the most to the increase in SUHI intensity (SUHII). Natural drivers are mediators indirectly contributing to variations in SUHII, influenced by anthropogenic drivers. In addition, we also found that the size of urbanized areas contributed the most to the increase in SUHI intensity (SUHII). The size of the urbanized areas had a positive non-linear relationship with SUHIIs. When the size was larger than 400 km2, the growth of SUHIIs maintained an equilibrium state. This study highlights the importance of impervious surface expansion for increasing SUHII. To confront SUHIs, it is necessary to perform proper urban planning.

More grazing, more damage? Assessed yield loss on agricultural grassland relates nonlinearly to goose grazing pressure

Abstract In recent decades, conflict between geese and agriculture has increased. Management practices to limit this conflict include concentrating geese in protected areas, derogation shooting or population reduction. To justify such management, we need to understand their effects on goose‐related damages, which requires an understanding of how yield loss is influenced by goose abundance and species interactions. We combined data from monthly goose counts and GPS‐tracked geese to estimate grazing pressures by barnacle, white‐fronted and greylag geese on agricultural grassland in Fryslân, the Netherlands. Using linear mixed models, we related this to damages assessed by professional inspectors. Our results show a positive nonlinear relationship between yield loss and barnacle goose grazing pressure, where assessed damage increases with a decelerating rate as grazing pressure increases. For white‐fronted geese, we find a negative relationship, while for greylag geese both positive and negative relationships occur. For each species, the relationship is influenced by the abundance of the other two. For barnacle geese, the relationship can be explained by selection of fields offering the best balance between food intake and energy expenditure, and by grass regrowth, with highest grazing pressures occurring over a longer time period. The results for the other species are likely due to spatial and temporal differences in foraging preferences compared to barnacle geese, where larger species avoid areas with highest damages. Synthesis and applications. Our results suggest that decreasing herbivore abundance may not translate directly to decreased yield loss, and management tools such as population reduction or derogation shooting should be used with care. Management aimed at concentrating geese in refuges could help to alleviate farmer–goose conflict, although further studies are required to determine if it would lead to damage reduction. We also find that not all species contribute equally to agricultural damage; care should be taken to ensure wildlife management targets the right species.

Insurance density and the digital economic development: a China perspective

The digital economy is an important starting point for China’s high-quality economic development, and insurance density is a key variable for measuring the development of the insurance industry. Can increasing insurance density promote digital economic development? Based on China’s provincial digital economic development index from 2013 to 2021, this study explores this question. The results show that a positive U-shaped nonlinear relationship between insurance density and digital economy, and there is an inflection point in insurance density. When insurance density is lower than the inflection point, an increase in insurance density will inhibit digital economic development; when it exceeds the inflection point, a further increase in insurance density will promote digital economic development. Furthermore, there is a positive U-shaped nonlinear relationship between insurance density and traditional technological innovation, which is conducive to digital economic development. As such, insurance density affects digital economic development through the transmission of traditional technological innovation. The findings have reference significance for developing countries to improve their insurance penetration rate and develop their digital economy to promote economic development.

Research on the Relationship Between Macroeconomic Indicators and Stock Market Value

The article first addresses the following questions: “Why does gross domestic product (GDP) rises, but the stock market value falls?”; “Among the macroeconomic factors, which factor has a greater impact on the promotion of investment value in the securities market?”. With these questions in mind, we put forward a hypothesis emphasizing on the impact of macroeconomic factors on the value of the stock market based on existing research and used the regression method to verify this hypothesis. The following conclusions were drawn: (1) variables that have a positive nonlinear relationship with stock market value include balance of payments surplus, rising GDP level, M1, the whole society’s fixed asset investment, and national per capita disposable income; (2) variables that have a negative nonlinear relationship with stock market value include deposit, loan interest rate, new RMB loan amount, consumer price index (CPI), and producer price index; (3) deposit reserve ratio has an S-shaped curve relationship with stock market value; (4) exchange rate has an inverted U-shaped curve relationship with stock market value.

Stream nitrogen uptake associated with suspended sediments: A microcosm study

Despite significant advances in our understanding of nitrogen (N) removal pathways along river networks, the role of water column processes remains largely understudied. This knowledge gap not only limits our capacity to determine N transport and retention in mid-to-large rivers but also hampers our understanding of N removal processes in smaller streams during stormflow conditions, in which significant increases in suspended sediment concentrations (SSC) typically occur. High SSC in the water column can provide abundant substrate for microbial growth and water column N uptake. However, storms of different size mobilize different quantities of sediment of varying properties and sizes, which can ultimately modulate water column N uptake rates in the stream during stormflows. To assess water column N uptake associated with suspended sediment particles of different sources and sizes, we quantified assimilatory and dissimilatory N uptake rates in a set of microcosms representing a gradient of sediment properties (organic matter, N content, and microbial activity) and surface area (fine vs. coarse size) availability. Water column assimilatory uptake (Used) ranged from 12.7 to 187.8 µg N [g sediment]−1 d−1 across all sediment sources and size fractions, and was higher on average than denitrification rates (DNsed) in agricultural and stream bank sediments but not in streambed sediments (mean DNsed = 240.9 ± 99 µg·N [g sediment]−1·d−1). Sediment-bound C in suspended sediment varied among sediment sources and was directly related to Used rates, but not to DNsed rates, which were less predictable and more variable. Overall, our results showed a positive nonlinear relationship between water column N uptake and SSC, while indicating that water column N uptake may scale differently to SSC depending on sediment source, and to a lesser degree, particle size. Because low, moderate, and large storms can mobilize different quantities of sediment in the watershed of different sources and sizes, it is likely that storm size will ultimately modulate the contribution of water column uptake during storm events to whole-reach N retention.

Climate change: north and south EU economies-an application of dynamic asymmetric panel data models.

The need for a cleaner environment and wealthier economies has been highly recognized by European Union (EU) policymakers of the last years, as evidenced by the creation of a plethora of laws and regulations for reducing carbon dioxide emissions while promoting the economic prosperity of EU countries. Indeed, many works have been done in this field, remarking on climate change’s impacts on economies and the need for determinant environmental policies inside the EU. This paper investigates the effect of climate change on economic growth using nonlinear dynamic panel methods for 15 countries of the EU in the period 1981–2019. Specifically, it is examined the impact of temperature, precipitation, and CO2 emissions on economic growth. So, autoregressive distributed lags (ARDL) methods were employed, overcoming cross-dependency and also considering linearity and nonlinearity. The results showed that economic growth has positive nonlinear relationship with long-run temperature, but in short-run they have a symmetric negative association. Moreover, precipitation has long-run negative and a short-run positive relationship with economic growth. However, when CO2 emissions are added, then model’s performance is decreased, and precipitation has a positive effect on economic growth, but all others, except from temperature increase, become insignificant. Finally, actions should be taken for more stable climate conditions and consistent environmental policies by EU countries.Graphical abstract

An analysis of the impact of human capital development on the regional economy's efficiency through the spatial correlation approach

Subject. This article examines the factors that determine the level of human capital in the regions of Russia. Objectives. The article aims to analyze the differentiation of the regions of Russia by level of human capital development. Methods. For the study, we used the methods of horizontal statistical analysis, nonlinear regression modeling, and spatial econometrics based on Moran's I measure. Results. The article confirms the opinion of some authors about the significant differentiation of the regions of Russia in terms of the level of human capital development and reveals a positive nonlinear relationship between the indicators of the gross regional product and the level of human capital of the region. Conclusions. Improving the quality of human capital in the region has a direct strong impact on the level of its economic development. A nonlinear form of the simulated dependence shows that there will come a time of marginal return on the use of human capital.