Potential Joint Effects Research Articles

Joint effects of ill-health, health shocks and social protection on the intensive margin of labour supply: evidence from Malawi

BackgroundThere is sparse evidence on the joint effects of ill-health, health shocks and social protection on the intensive margin of labour supply, particularly in developing countries. We interact ill-health and health shocks with access to social protection and estimate their joint effects on weekly hours of work.MethodsWe employ a zero-inflated Poisson model to assess joint effects of ill-health, health shocks and social protection on weekly hours of work exploiting pooled repeated cross-sectional data from Malawi.ResultsWe find that overall, individuals who suffered from ill-health or a health shock, including an illness/injury, a hospital admission or a chronic illness and benefited from social protection, reduced their weekly hours of work.ConclusionsThe study provides novel empirical evidence on the potential joint effects of ill-health, health shocks and social protection on the intensive margin of labour supply, shedding light on the role social protection can play in developing countries.

Ambient PM2.5, household environment and preterm birth: A birth cohort study in Shandong, China

BackgroundThe associations between fine particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5) and risk of preterm birth (PTB) are inconsistent, and the effect of household environment on PTB is largely unclear. AimTo investigate the association of ambient PM2.5 throughout pregnancy, household environmental factors and PTB, with further exploration of their potential interaction and joint effect on PTB. MethodsThe study included 5888 pregnant women between 2018 and 2021 in Weifang Maternal and Child Health hospital of Shandong, China. Maternal exposure to PM2.5 was extracted from ChinaHighAirPollutants datasets according to individual home address. Household environmental information including residential floor level, double-glazed window, heating fuel, cooking, smoking and window ventilation was collected by questionnaires at enrollment. PTB was defined as a birth before 37 completed weeks of gestation. General additive models were applied to examine the associations of PM2.5 exposure, household environment and PTB. ResultsOne-unit increase of PM2.5 throughout pregnancy was associated with significantly increased risk of PTB (OR = 1.069, 95% CI: 1.037, 1.103). In contrast, installation of double-glazed windows (OR = 0.763, 95% CI: 0.589, 0.990) and residential floor level of the 5th floor or above (OR = 0.746, 95% CI: 0.583, 0.955) were found to be associated with significantly reduced risk of PTB. The stratified analyses demonstrated that the protective associations remained among those with high PM2.5 exposure, urban residence, middle SES level and cesarean delivery. A negative interaction between residential floor level and PM2.5 exposure on PTB, and joint effect of installation of double-glazed windows plus residential floor level of the 5th floor or above on PTB were observed. ConclusionsThis study found the adverse effect of PM2.5 during the pregnancy on PTB, and identified protective associations between installing double-glazed windows, living on the 5th floor or above and PTB in relatively polluted regions.

Association between being large for gestational age and cardiovascular metabolic health in children conceived from assisted reproductive technology: a prospective cohort study.

To the best of our knowledge, no study has investigated the potential joint effect of large for gestational age (LGA) and assisted reproductive technology (ART) on the long-term health of children. This was a prospective cohort study that recruited children whose parents had received ART treatment in the Center for Reproductive Medicine, Shandong Provincial Hospital, affiliated to Shandong University, between January 2006 and December 2017. Linear mixed model was used to compare the main outcomes. The mediation model was used to evaluate the intermediary effect of body mass index (BMI). 4138 (29.5%) children born LGA and 9910 (70.5%) children born appropriate for gestational age (AGA) were included in the present study. The offspring ranged from 0.4 to 9.9years. LGAs conceived through ART were shown to have higher BMI, blood pressure, fasting blood glucose, fasting insulin, and homeostatic model assessment of insulin resistance values, even after controlling for all covariates. The odds of overweight and insulin resistance are also higher in LGA subjects. After adjusting for all covariates, LGAs conceived through ART had BMI and BMI z-scores that were 0.48kg/m2 and 0.34 units greater than those of AGAs, respectively. The effect of LGA on BMI was identified as early as infancy and remained consistently significant throughout pre-puberty. Compared to AGA, LGA children conceived from ART were associated with increased cardiovascular-metabolic events, which appeared as early as infancy and with no recovery by pre-puberty.

Unraveling the link between heavy metals, perfluoroalkyl substances and depression: Insights from epidemiological and bioinformatics strategies

Heavy metals and per- and polyfluoroalkyl substances (PFASs) have become particularly important when studying the development of depression, a common illness that severely restricts psychosocial functioning and diminishes quality of life. Therefore, the potential joint effects of heavy metal and PFAS exposure on depression, as well as the underlying mechanisms involved, were investigated by using integrated epidemiological and bioinformatic approaches in the present study. A thorough analysis of 7301 samples from the National Health and Nutrition Examination Survey (NHANES) cycles that occurred between 2005 and 2018 was performed. Single-exposure studies have shown that cadmium exposure is positively associated with depression, whereas perfluorooctanesulfonic acid (PFOS) exposure and perfluorodecanoic acid (PFDE) exposure are negatively associated with depression. Furthermore, the Bayesian kernel machine regression (BKMR) and quantile g-computation (QGcomp) models were employed to investigate the collective impact of exposure to mixed metals on depression. Cadmium emerged as the principal contributor to depression. Moreover, the addition of PFAS to the metal mixture had an antagonistic effect on depression, with PFOS having the most prominent influence. Analysis of the effects of co-exposure to cadmium and PFOS confirmed the presence of an antagonistic effect. The inflection points of cadmium and PFOS were determined to be −1.11 and 2.27, respectively. Additionally, exposure to cadmium and PFOS had the opposite effects on two crucial pathways, namely, the rap1 and calcium signaling pathways, which involve core genes related to depression such as ADORA2A, FGF2, and FGFR1. These findings have significant implications for future studies and provide new strategies for exploring the mechanisms underlying co-exposure effects.

Hybrid ARIMA-IIS Approach for Wheat Yield Forecasting: An Integrated Approach

This study explores the application of a hybrid approach, combining the Impulse Indicator Saturation (IIS) method with an ARIMA(x) model, to forecast wheat yield. The IIS method is employed to find potential impulse responses, which are then integrated into the ARIMA(x) framework. The IIS method captures the potential joint effects of the weather, climate and other inputs on the data generating process of the wheat yield time series. The performance of the hybrid ARIMA(x) model is compared with that of the standalone ARIMA model using various error metrics, including Mean Squared Error (MSE), Mean Absolute Percentage Error (MAPE), and Mean Absolute Deviation (MAD). Additionally, model selection criteria such as the Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Schwarz Bayesian Information Criterion (SBIC), and Hannan-Quinn Criterion (HQ) are used to identify the optimal model for forecasting. The training data of wheat yield from 1948-2018 was used to fit both the ARIMA and ARIMA(x) models, while the remaining observations until 2023 are used for model validation. The results of the study reveal that the hybrid ARIMA(x) model exhibits superior forecasting ability, demonstrating lower error metrics compared to the standalone ARIMA model. Notably, the ex-ante forecasts for the 2023-24 period predict a wheat production of 29.916 million tons using the ARIMA(x) model and 29.656 million tons using the ARIMA (2,1,2) model. These findings underscore the efficacy of the hybrid approach in enhancing production forecasting accuracy, thereby serving as a valuable basis for early warning systems to address potential demand and supply gaps in wheat production.

Daily Idea Generation and Employee Creative Performance: Effect of Day-Level Congruence Between Felt Responsibility for Change and Willingness to Take Risks

This study explores a potential joint effect between two proactive motives on creative performance. Departing from the assumption of motivation as a relatively stable between-person construct, we also pay attention to the within-person process to examine how daily fluctuations of proactive motives affect daily idea generation, leading to creative performance. Specifically, drawing on job demands–resources theory, we theorize a joint effect of two proactive motives at the within-person level: daily felt responsibility for change (DFRC) and daily willingness to take risks (DWTR). We test our hypotheses by analyzing data collected from 135 employees and their supervisors by using the experience sampling method followed by multiwave field surveys. Daily idea generation is high when the DFRC and DWTR have high congruence, particularly when both motives are high rather than low. In addition, daily idea generation mediates the effect of the DFRC and DWTR congruence on employee creative performance as appraised by supervisors. Moreover, seeking feedback from coworkers strengthens the indirect effect of the DFRC and DWTR congruence on employee creative performance via daily idea generation. This study offers a fine-grained view of motivational mechanisms and employee social behavior that lead to creative performance in the workplace.

Feelings of tense and risk of incident dementia: A prospective study of 482,360 individuals

BackgroundThe relationship between feelings of tense, as a significant emotional distress, and dementia remains unclear. This study aimed to evaluate the association between feelings of tense and dementia. MethodsIn UK Biobank, feelings of tense were measured with a standard item. The primary outcome was all cause of dementia (ACD) and its subtypes (Alzheimer's disease (AD), vascular dementia (VD), and other dementia). Cox regression models analyzed the association between feelings of tense and dementia risk, while linear regression examined the correlation with neuroimaging outcomes. The potential association and joint effects of AD and tenseness were evaluated based on the established genetic risk score (GRS). ResultsDuring a median follow-up of 12.7 years among 482,360 participants, 7331 dementia cases were identified. Individuals with feelings of tense had a significantly increased risk of ACD (HR, 1.194; 95 % CI: 1.115–1.278), VD (HR, 1.164; 95 % CI: 1.007–1.346), and other dementia (HR, 1.181; 95 % CI: 1.081–1.289), but not AD in multi-adjusted models. This association persisted across various sensitivity analyses and exhibited some heterogeneity in subgroup analyses. Furthermore, feelings of tense are associated with total brain volume shrinkage, higher white matter hyperintensities, and decreased partial subcortical volume, particularly in the hippocampus. No interaction between tenseness and AD genetic susceptibility was observed (P for interaction =0.346). LimitationsOur study only considered feelings of tense measured at a one-time point. ConclusionsOur findings demonstrate a significant association between feeling of tense and elevated dementia risk, indicating that tenseness could serve as a modifiable psychological determinant for dementia.

A brief review on the assessment of potential joint effects of complex mixtures of contaminants in the environment

Many contaminants can have long-term effects on organisms when they are exposed to low concentrations for extended periods. This review presents new methods for identifying the effects of chemical mixtures.

Metabolic Perturbations Associated with an Exposure Mixture of Per- and Polyfluoroalkyl Substances in the Atlanta African American Maternal-Child Cohort.

Prenatal exposure to single chemicals belonging to the per- and polyfluoroalkyl substances (PFAS) family is associated with biological perturbations in the mother, fetus, and placenta, plus adverse health outcomes. Despite our knowledge that humans are exposed to multiple PFAS, the potential joint effects of PFAS on the metabolome remain largely unknown. Here, we leveraged high-resolution metabolomics to identify metabolites and metabolic pathways perturbed by exposure to a PFAS mixture during pregnancy. Targeted assessment of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS), along with untargeted metabolomics profiling, were conducted on nonfasting serum samples collected from pregnant African Americans at 6-17 weeks gestation. We estimated the overall mixture effect and partial effects using quantile g-computation and single-chemical effects using linear regression. All models were adjusted for maternal age, education, parity, early pregnancy body mass index, substance use, and gestational weeks at sample collection. Our analytic sample included 268 participants and was socioeconomically diverse, with the majority receiving public health insurance (78%). We observed 13.3% of the detected metabolic features were associated with the PFAS mixture (n = 1705, p < 0.05), which was more than any of the single PFAS chemicals. There was a consistent association with metabolic pathways indicative of systemic inflammation and oxidative stress (e.g., glutathione, histidine, leukotriene, linoleic acid, prostaglandins, and vitamins A, C, D, and E metabolism) across all metabolome-wide association studies. Twenty-six metabolites were validated against authenticated compounds and associated with the PFAS mixture (p < 0.05). Based on quantile g-computation weights, PFNA contributed the most to the overall mixture effect for γ-aminobutyric acid (GABA), tyrosine, and uracil. In one of the first studies of its kind, we demonstrate the feasibility and utility of using methods designed for exposure mixtures in conjunction with metabolomics to assess the potential joint effects of multiple PFAS chemicals on the human metabolome. We identified more pronounced metabolic perturbations associated with the PFAS mixture than for single PFAS chemicals. Taken together, our findings illustrate the potential for integrating environmental mixture analyses and high-throughput metabolomics to elucidate the molecular mechanisms underlying human health.

Evidence of interactive effects of late-pregnancy exposure to air pollution and extreme temperature on preterm birth in China: a nationwide study

Perinatal exposure to heat and air pollution has been shown to affect the risk of preterm birth (PTB). However, limited evidence exists regarding their joint effects, particularly in heavily polluted regions like China. This study utilized data from the ongoing China Birth Cohort Study, including 103 040 birth records up to December 2020, and hourly measurements of air pollution (PM2.5, NO2, and O3) and temperature. We assessed the nonlinear associations between air pollution and temperature extereme exposures and PTB by employing generalized additive models with restricted cubic slines. Air pollution and temperature thresholds (corresponding to minimum PTB risks) were determined by the lowest Akaike Information Criterion. We found that maternal exposures to PM2.5, NO2, O3, and both low and high temperature during the third trimester of pregnancy were independently associated with increased risk of PTB. The adjusted risk ratios for PTB of PM2.5, O3, NO2, and temperature at the 95th percentile against thresholds were 1.32 (95% CI: 1.23, 1.42), 1.33 (95% CI: 1.18, 1.50), 1.44 (95% CI: 1.33, 1.56) and 1.70 (95% CI: 1.56, 1.85), respectively. Positive additive interactions [relative excess risk due to interaction (RERI) > 0] of PM2.5–high temperature (HT), O3–HT, O3–low temperature (LT) are identified, but the interactive effects of PM2.5 and LT were negative (RERI < 0). These observed independent effects of air pollution and temperature, along with their potential joint effects, have important implications for future studies and the development of public health policies aimed at improving perinatal health outcomes.

Influence of analytic methods, data sources, and repeated measurements on the population attributable fraction of lifestyle risk factors

Population attributable risk (PAR%) reflects the preventable fraction of disease. However, PAR% estimates of cancer have shown large variation across populations, methods, data sources, and timing of measurements. Three statistical methods to estimate PAR% were identified from a systematic literature review: the Levin’s formula, the comparative incidence rate method, and the comparative risk assessment method. We compared the variations in PAR% of postmenopausal breast cancer in the Nurses’ Health Study to evaluate the influence by method choice, source of prevalence data, use of single vs repeated exposure measurements, and potential joint effects of obesity, alcohol, physical activity, fruit and vegetable intake. Across models of the three methods, the estimated PAR% using repeated measurements were higher than that using baseline measurement; overall PAR% for the baseline, simple update, and cumulative average models were 13.8%, 21.1%, 18.6% by Levin’s formula; 13.7%, 28.0%, 31.2% by comparative risk assessment; and 17.4%, 25.2%, 29.3% by comparative incidence rate method. The estimated PAR% of the combination of multiple risk factors was higher than the product of the individual PAR%: 18.9% when assuming independence and 31.2% when considering the risk factors jointly. The three methods provided similar PAR% based on the same data source, timing of measurements, and target populations. However, sizable increases in the PAR% were observed for repeated measures over a single measure and for calculations based on achieving all recommendations jointly rather than individually.

Association between metabolic syndrome and gastric cancer risk: results from the Health Examinees Study.

Previous studies suggested that metabolic syndrome (MetS) might create a pro-cancer environment and increase cancer incidence. However, evidence on the risk of gastric cancer (GC) was limited. This study aimed to evaluate the association between MetS and its components and GC in the Korean population. Included were 108,397 individuals who participated in the large-scale prospective cohort study, the Health Examinees-Gem study during 2004-2017. The multivariable Cox proportional was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) on the association between MetS and its components with GC risk. Age was used as the time scale in the analyses. The stratified analysis was performed to determine the joint effect of lifestyle factors and MetS on GC risk in different groups. During the mean follow-up of 9.1years, 759 cases of newly diagnosed cancer (408 men and 351 women) were identified. Overall, participants with MetS had a 26% increased risk of GC than those without MetS (HR 1.26; 95% CI 1.07-1.47); the risk increased with the number of MetS components (p for trend 0.01). Hypertriglyceridemia, low HDL-cholesterol, and hyperglycemia were independently associated with the risk of GC. The potential joint effect of MetS and current smokers (p for interaction 0.02) and obesity (BMI ≥ 25.0) (p for interaction 0.03) in GC. In this prospective cohort study, we found that MetS were associated with an increased risk of GC in the Korean population. Our findings suggest that MetS may be a potentially modifiable risk factor for GC risk.

Mortality Associated With Occupational Exposure in Helsinki, Finland-A 24-Year Follow-up.

Our objective was to study mortality related to different obstructive lung diseases, occupational exposure, and their potential joint effect in a large, randomized population-based cohort. We divided the participants based on the answers to asthma and chronic obstructive pulmonary disease (COPD) diagnoses and occupational exposure and used a combined effects model and compared the results to no asthma or COPD with no occupational exposure. High exposure had a hazards ratio (HR) of 1.34 (1.11-1.62) and asthma and COPD coexistence of 1.58 (1.10-2.27). The combined effects of intermediate exposure and coexistence had an HR of 2.20 (1.18-4.09), high exposure with coexistence of 1.94 (1.10-3.42) for overall mortality, and sub-HR for respiratory-related mortality of 3.21 (1.87-5.50). High occupational exposure increased overall but not respiratory-related mortality hazards, while coexisting asthma and COPD overall and respiratory-related hazards of mortality.

Combined Exposure to 33 Trace Elements and Associations With the Risk of Oral Cancer: A Large-Scale Case-Control Study.

BackgroundTrace elements exist widely in the natural environment and mostly enter the human body through drinking water or various types of food, which has raised increasing health concerns. Exposure to a single or a few trace elements has been previously reported to be associated with oral cancer risk, but studies on other elements and combined effects are limited. This study aimed to comprehensively evaluate the independent and joint effects of 33 trace elements on oral cancer risk.MethodsThe concentrations of 33 trace elements from the serum samples of 463 cases and 1,343 controls were measured using inductively coupled plasma mass spectrometry (ICP-MS). Propensity score matching was used to minimize the impact of potential confounders. Conditional logistic regression was utilized to evaluate the association of each element individually with oral cancer risk. Quantile g-computation and Bayesian kernel machine regression (BKMR) models were used to assess the joint effect of the overall element mixture and interactions.ResultsIn single-element models, essential elements (Cu, Se, Zn, Sr, and Cr) and non-essential elements (As, Li, Th, Ce, Ti, and Sc) showed significant association with oral cancer risk. In multiple-element models, a quartile increase in overall non-essential elements was observed for a significant inverse association with oral cancer risk (β = −3.36, 95% CI: −4.22 to −2.51). The BKMR analysis revealed a potential beneficial joint effect of essential metals on the risk of oral cancer. Among these, higher levels of serum Zn and V exhibited an adverse effect, while serum Sr, Se, and Cu displayed favorable effects when all other essential elements were fixed at 25th or 50th percentiles. Of note, Se performed complex interactions among essential metals. As for non-essential elements, there were greater effect estimates for serum Th, Li, and Y when all other elements were held at the 75th percentile.ConclusionThis study provides supportive evidence that the overall mixture effect of essential and non-essential elements might be associated with oral cancer risk, especially for serum Zn, V, Cu, Sr, Se, Th, Li, and Y. Extensive prospective studies and other experiments are warranted to confirm our findings.

Super-taxon in human microbiome are identified to be associated with colorectal cancer

BackgroundMicrobial communities in the human body, also known as human microbiota, impact human health, such as colorectal cancer (CRC). However, the different roles that microbial communities play in healthy and disease hosts remain largely unknown. The microbial communities are typically recorded through the taxa counts of operational taxonomic units (OTUs). The sparsity and high correlations among OTUs pose major challenges for understanding the microbiota-disease relation. Furthermore, the taxa data are structured in the sense that OTUs are related evolutionarily by a hierarchical structure.ResultsIn this study, we borrow the idea of super-variant from statistical genetics, and propose a new concept called super-taxon to exploit hierarchical structure of taxa for microbiome studies, which is essentially a combination of taxonomic units. Specifically, we model a genus which consists of a set of OTUs at low hierarchy and is designed to reflect both marginal and joint effects of OTUs associated with the risk of CRC to address these issues. We first demonstrate the power of super-taxon in detecting highly correlated OTUs. Then, we identify CRC-associated OTUs in two publicly available datasets via a discovery-validation procedure. Specifically, four species of two genera are found to be associated with CRC: Parvimonas micra, Parvimonas sp., Peptostreptococcus stomatis, and Peptostreptococcus anaerobius. More importantly, for the first time, we report the joint effect of Parvimonas micra and Parvimonas sp. (p = 0.0084) as well as that of Peptostrepto-coccus stomatis and Peptostreptococcus anaerobius (p = 8.21e-06) on CRC. The proposed approach provides a novel and useful tool for identifying disease-related microbes by taking the hierarchical structure of taxa into account and further sheds new lights on their potential joint effects as a community in disease development.ConclusionsOur work shows that proposed approaches are effective to study the microbiota-disease relation taking into account for the sparsity, hierarchical and correlated structure among microbes.

I Know It Is Not Real (And That Matters) Media Awareness vs. Presence in a Parallel Processing Account of the VR Experience

Inspired by the widely recognized idea that in VR/XR, not only presence but also encountered plausibility is relevant (Slater, Phil. Trans. R. Soc. B, 2009, 364 (1535), 3549–3557), we propose a general psychological parallel processing account to explain users’ VR and XR experience. The model adopts a broad psychological view by building on interdisciplinary literature on the dualistic nature of perceiving and experiencing (mediated) representations. It proposes that perceptual sensations like presence are paralleled by users’ belief that “this is not really happening,” which we refer to asmedia awareness. We review the developmental underpinnings of basic media awareness, and argue that it is triggered in users’ conscious exposure to VR/XR. During exposure, the salience of media awareness can vary dynamically due to factors like encountered sensory and semantic (in)consistencies. Our account sketches media awareness and presence as two parallel processes that together define a situation as a media exposure situation. We also review potential joint effects on subsequent psychological and behavioral responses that characterize the user experience in VR/XR. We conclude the article with a programmatic outlook on testable assumptions and open questions for future research.

Chemical Mixtures in Household Environments: In Silico Predictions and In Vitro Testing of Potential Joint Action on PPARγ in Human Liver Cells

There are thousands of chemicals that humans can be exposed to in their everyday environments, the majority of which are currently understudied and lack substantial testing for potential exposure and toxicity. This study aimed to implement in silico methods to characterize the chemicals that co-occur across chemical and product uses in our everyday household environments that also target a common molecular mediator, thus representing understudied mixtures that may exacerbate toxicity in humans. To detail, the Chemical and Products Database (CPDat) was queried to identify which chemicals co-occur across common exposure sources. Chemicals were preselected to include those that target an important mediator of cell health and toxicity, the peroxisome proliferator activated receptor gamma (PPARγ), in liver cells that were identified through query of the ToxCast/Tox21 database. These co-occurring chemicals were thus hypothesized to exert potential joint effects on PPARγ. To test this hypothesis, five commonly co-occurring chemicals (namely, benzyl cinnamate, butyl paraben, decanoic acid, eugenol, and sodium dodecyl sulfate) were tested individually and in combination for changes in the expression of PPARγ and its downstream target, insulin receptor (INSR), in human liver HepG2 cells. Results showed that these likely co-occurring chemicals in household environments increased both PPARγ and INSR expression more significantly when the exposures occurred as mixtures vs. as individual chemicals. Future studies will evaluate such chemical combinations across more doses, allowing for further quantification of the types of joint action while leveraging this method of chemical combination prioritization. This study demonstrates the utility of in silico-based methods to identify chemicals that co-occur in the environment for mixtures toxicity testing and highlights relationships between understudied chemicals and changes in PPARγ-associated signaling.

Ammonia in the presence of nano titanium dioxide (nano-TiO2) induces greater oxidative damage in the gill and liver of female zebrafish

Water pollution caused by a highly hazardous chemical ammonia and a widespread application nanomaterials-nano titanium dioxide (n-TiO2) in nature water has attracted extensive concern of the world. However, the potential joint effects of the two factors are unknown. Aim to investigate the potential interactive effects of ammonia and n-TiO2 and the behind mechanisms, adult female zebrafish (Danio rerio) were co-exposed for 8 weeks by total ammonia nitrogen (TAN; 0, 3, 30 mg/L) and n-TiO2 (0, 0.1, 1 mg/L) in different combination conditions based on a full-factorial design. The analysis of absorption kinetics confirmed that n-TiO2 could absorb free ammonia (NH3) in aqueous solution and the loss rate of free NH3 increased with the rise of n-TiO2 concentration. Consistent with this, free NH3 concentrations in the gill and liver were higher in the presence of n-TiO2 compared to TAN exposure alone. The increases of MDA and PC concentrations in the gill and liver of fish indicated that TAN and n-TiO2 alone or in combination caused oxidative stress. Simultaneously, the activity and transcription of antioxidant enzymes (T-SOD, CuZn-SOD, Mn-SOD, CAT, GPx and GST) as well as antioxidant GSH contents were extensively inhibited by TAN and n-TiO2 via Nrf2-Keap1 signaling. The significant interactive effects of TAN and n-TiO2 were detected on levels of GSH, GST and gstr1 mRNA in the gill, and on levels of GSH, T-SOD, Mn-SOD, CAT levels as well as gpx1a and keap1 mRNAs in the liver, implying synergistic toxic risk of TAN and n-TiO2. The more severe histopathological alterations and higher IBR analysis in co-treatment groups further proved that the existence of n-TiO2 excavated ammonia-induced toxicity in the gill and liver, especially in liver. In conclusion, ammonia and n-TiO2 have a synergistic toxic risk of fish health because ammonia and n-TiO2 cause oxidative-antioxidative imbalance by inducing ROS overproduction.

Innovation, trade barriers and exports: evidence from manufacturing firms in ASEAN countries

PurposeThis study aims to integrate both internal and external factors to examine the effect of innovation and perceived trade barriers on firms’ export activity. In particular, the authors expand the scope of innovation into both technological (product and process) and non-technological (marketing and management) innovation. Furthermore, the authors examine the potential joint effect of perceived customs and trade barriers on firms.Design/methodology/approachThe authors empirically test the hypotheses by using firm-level data from the World Bank Enterprise Survey during the most recent year available for each ASEAN country, together with both firm- and country-level controls from various data sources. Specifically, the final sample for analysis includes 3,602 firms from Cambodia (100), Indonesia (1157), Laos (99), Malaysia (445), the Philippines (719), Thailand (572) and Vietnam (510).FindingsFirst, the results show that firm-specific innovation capabilities (including non-technological of managerial innovation) do matter for explaining export propensity. Furthermore, in contexts in which location-bound advantages are prevalent, the effects of innovation may disappear and further deteriorate performance in the post-entry stage. Second, the findings support the notion regarding the prevalence of country- over firm-specific advantages for the international expansion of companies from ASEAN countries. More specifically, this study holds that innovation does not matter for export intensity and that factors related to the location’s institutions appear to be more important.Originality/valueFirst, it acknowledges and examines the effect of not only technological innovation, but also non-technological innovation on export intention. Second, the paper measures the institutional effect at the firm level, rather than as a country-specific factor, to better understand the combined effect of internal and external variables on firms’ export strategy. Furthermore, it performs a cross-country analysis while controlling for other confounding firm and macro factors. Third, the authors test the model on both pre-entry (export propensity) and post-entry (export intensity) stages. Finally, the study responds to calls for research that examines the international competitive advantages of firms from ASEAN countries.

Potential joint effects of perceptions related to COVID-19 and future social development on depressive symptoms: a Chinese population-based study

Background The COVID-19 pandemic has caused significant negative socio-political, economic, and psychological consequences. Aims To investigate the impact of individual-level (illness representations of COVID-19) and structurally derived (anticipated social-political development in the economy, security, and social harmony in the next year) factors, and their potential moderation effects on depressive symptoms. Methods An anonymous population-based telephone survey was conducted among the general public of Hong Kong, China during 3–10 April 2020 (n = 300, response rate 56%). Depressive symptoms were assessed by the validated Chinese version of the Patient Health Questionnaire-9. Results Of the participants, 8.7% showed probable moderate-to-severe depression. Hierarchical linear regression models showed that illness representations of personal/treatment control and emotional responses and anticipated deterioration in social harmony were independently and significantly associated with depressive symptoms. Anticipated deterioration in security significantly moderated the associations between perceived consequence/treatment control of COVID-19 and depressive symptoms, such that the associations were stronger among people who anticipated a strong deterioration in security. Conclusions The findings suggested that perceptions of COVID-19 and future social-political development jointly and interactively contributed to depressive symptoms during the COVID-19 pandemic. Mental health professionals and promotions should take the multiple-level mental health determinants into account.