Correlation analysis of norepinephrine dose on enteral nutrition tolerance and prognosis in patients with septic shock.

BACKGROUND: To explore correlation between the dose of norepinephrine and the timing of starting enteral nutrition in septic shock (SS) patients. METHODS: Totally 150 SS patients treated with enteral nutrition (EN) in Shiyan People's Hospital from Dece20 to July 2022 were included in this retrospective analysis. Patients were divided into tolerance group (n = 97) and intolerance group (n = 53) according to whether EN was tolerated or not. The study indexes include baseline characteristics [gender, age, weight, body mass index (BMI), scores of acute physiology and chronic health evaluation II system (APACHE II), comorbidity, time in-hospital, prognosis], clinical indexes [mean arterial pressure (MAP), time of mechanical ventilation (MV), norepinephrine dose at the time of starting EN, using of sedative drug, gastrointestinal motility drugs and cardiotonic drugs], EN indexes (timing of starting EN, speed of EN infusion, calorie of EN per day, EN target percent), and gastrointestinal intolerance index [residual gastric volume > 250 ml, vomiting, aspiration, gastrointestinal bleeding, blood lactic acid (BLA)]. Student-t test and Mann-Whitney test were used for test of measurement data. Chi-square test and fisher exact test were used for comparison of categorical data. RESULTS: There were 51 (52.58%) male and 46 (47.42%) female patients with a median age of 66.4 ± 12.8 years old in tolerance group. There were 29 (54.72%) male and 24 (45.28%) female patients with a median age 67.3 ± 12.5 years old in intolerance group. The weight and BMI were significantly higher in intolerance group than those of tolerance group (both P < 0.001). There was no significant difference of comorbidity rate between two groups (all P > 0.05). Before the overlapping time of EN and norepinephrine, there were significantly more patients receiving gastrointestinal motility drugs in intolerance group compared with tolerance group (58.49% vs. 20.62%, P < 0.001). Patients in tolerance group had significantly less residual volume in gastric than that of intolerance group (188.00 ± 52.32 vs. 247.83 ± 34.95, P < 0.001). The rate of residual volume in gastric > 250ml (9.28% vs. 37.74%, P < 0.001), vomiting (15.46% vs. 35.85%, P = 0.004) and aspiration(16.49% vs. 33.96%, P = 0.018) were significantly lower in tolerance group than those of intolerance group. The BLA in tolerance group was significantly lower than that of intolerance group (1.84 ± 0.63 vs. 2.90 ± 1.5 3mmol/L,P < 0.001). There were significantly more patients with increased BLA (75.47% vs. 30.93%, P < 0.001) and > 2mmol BLA rising (43.40% vs. 8.25%, P < 0.001) in intolerance group than those of tolerance group. Patients in tolerance group had significantly lower time of starting EN (40.97 ± 9.53 vs. 49.85 ± 11.61 h, P < 0.001), dose of NE(0.23 ± 0.07 vs. 0.28 ± 0.10 ug/kg/min, P = 0.049), mortality in hospital (18.56% vs. 49.06%, P < 0.001) and mortality in ICU (16.49% vs. 37.74%, P < 0.001) compared with intolerance group. The EN target percent (92.78% vs. 56.60%, P < 0.001) and calorie of EN during overlapping period (20.22 ± 5.99 vs. 16.21 ± 2.52 kcal/kg/day, P < 0.001) in tolerance group were significantly higher than those of intolerance group. CONCLUSIONS: SS patients should be comprehensively evaluated according to their condition. Obese patients are more prone to EN intolerance, and those who can tolerate EN should be implemented as soon as possible. The use dose of NE is significantly related to EN tolerance. When the use dose is low, EN tolerance is greater.

Analysis of Prognostic Risk Factors of Sepsis Patients With Myocardial Injury: Six-month Survival Outcome.

Context: Sepsis is a systemic, comprehensive inflammatory response that can induce serious complications for patients. No uniform definition and diagnostic criteria exist internationally for sepsis related to myocardial injury. Studying factors affecting prognosis for sepsis patients with myocardial injury can be helpful in providing a theoretical basis for clinical diagnosis and treatment. Objective: The study intended to explore the predictors of the short-term prognosis for septic patients with myocardial injury and to provide a theoretical basis for improving that prognosis. Design: The research team performed a retrospective study. Setting: The study took place at the Renmin Hospital at Hubei University of Medicine in Shiyan, Hubei, China. Participants: Participants were 138 patients with sepsis and myocardial injury at the hospital between January 2018 and February 2021. Groups: The research team divided participants into a survival group with 114 patients and a mortality group with 24 patients, based on their survival status at six months after being in the hospital. Outcome Measures: The research team collected and analyzed the following data: (1) demographic and clinical characteristics, such as age, gender, underlying disease, and disease severity; (2) echocardiographic indicators, including left ventricular ejection fraction (LVEF), stroke volume (SV), left ventricular end systolic dimension (LVESD), and left ventricular end diastolic dimension (LVEDD); and (3) myocardial injury markers and inflammatory factors, including white blood cell (WBC) count and levels of cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), creatine kinase (CK), C-reactive protein (CRP), and procalcitonin (PCT). Results: The six-month mortality rate for patients with sepsis with myocardial injury was 17.39%. Compared to the survival group at participants' initial visits to the hospital, the mortality group had a significantly greater age (P = .046), sepsis severity (P < .001), heart rate (P < .001), APACHE II score (P < .001), SOFA score (P < .001), and use of vasoactive drugs (P = .002), and its length of hospital stay was significantly shorter (P < .001). The mortality group's LVEF was significantly lower than that of the survival group (P < .001). The mortality group's levels of WBC, cTnI, NT-proBNP, CK, CRP, and PCT were significantly higher than those in survival group (all P < .001). The univariate analysis found that an age>64 years (P < .001), a high APACHE II score (P < .001), an elevated cTnI (P = .017), an elevated NT-proBNP (P = .029), an elevated CK (P < .001), an elevated CRP (P = .031), and an elevated PCT (P < .001) were risk factors for a poor prognosis for patients. Multifactor logistic regression analysis showed that the risk factors for death were an age > 64 years (P < .001), a high APACHE II score (P < .001), and elevated levels of cTnI (P = .013), NT-proBNP (P < .001), CK (P < .001), CRP (P < .001), and PCT (P = .009). Conclusion: In summary, risk factors for poor prognosis in septic patients with myocardial injury included age>64 years, high APACHE II, elevated cTnI, elevated NT-proBNP, elevated CK, elevated CRP, and elevated PCT.

Estimating ecological sustainability in the Guangdong-Hong Kong-Macao Greater Bay Area, China: Retrospective analysis and prospective trajectories.

In recent decades, rapid urbanization and intensified global climate change have resulted in a significant difference of environment and resources distribution on space, which would cause trouble for accurate assessment of regional ecological sustainable development, especially in the large urban agglomerations. The parameters used in previous assessment methods have normally ignored spatial heterogeneity, leading to deviations in the evaluation accuracies against the context above. By incorporating remote sensing technology, this study proposed an improved emergy ecological footprint (EEF) method and a novel ecological sustainability index to comprehensively analyze the variability of ecological security states (ESS) from 1994 to 2018 in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) and to predict its sustainable growth potential based on a combined factorial decomposition and scenario analysis. Results showed that the pixel-based emergy analysis revealed significant heterogeneity over time and space under the impact of climate change and intense land use activities during the study period. The emergy carrying capacity per capita (ecc) and the emergy ecological footprint per capita (eef) also showed a significant difference between the nine cities in the GBA. In addition, the traditional EEF method, which does not consider the spatiotemporal variation, has indeed overestimated the GBA's ecc by 15% compared with our results. The ESS of the GBA gradually worsened from slight insecurity in the 1990s to moderate insecurity in 2018. If the current trends in socio-economic activities and climate change continue according to the RCP8.5 scenario in the IPCC, the ESS of the GBA will reach the extreme insecurity state in 2050. However, our scenarios show that industrial structure adjustment, energy structure optimization, and especially biological resource conservation can reduce the EFI by approximately 6.52%, 23.4%, and 30.6%, respectively. Consequently, effective implementation of the above measures can limit the increase both in emergy ecological deficit and emergy ecological footprint intensity (EFI) and, together, contribute to a higher security status in the GBA in 2050.

Silence of long intergenic noncoding RNA HOTAIR ameliorates oxidative stress and inflammation response in ox-LDL-treated human macrophages by upregulating miR-330-5p.

Evidence of the involvement of long noncoding RNAs (lncRNAs) in atherosclerosis is growing but still not well characterized. Here, we concentrated on the biological roles of lncRNA HOX transcription antisense RNA (HOTAIR) in atherosclerosis. In our study, we found that oxidized low-density lipoprotein (ox-LDL) induced human macrophages THP-1 cells apoptosis dose dependently and time dependently. Meanwhile, HOTAIR was significantly increased in THP-1 cells treated with ox-LDL. Then, HOTAIR was modulated by infection of LV-short hairpin RNA (shRNA) and LV-HOTAIR into THP-1 cells. As displayed, CD36, Oil Red O staining levels, total cholesterol, triglyceride levels and dil-ox-LDL uptake rate were greatly repressed by the silence of HOTAIR while triggered by overexpression of HOTAIR. Moreover, knockdown of HOTAIR suppressed reactive oxygen species, malondialdehyde levels, increased superoxide dismutase activity and cell apoptosis were also restrained. Reversely, overexpression of HOTAIR exhibited an opposite phenomenon. In addition, interleukin 6 (IL-6), IL-1ß, cyclo-oxygenase 2, and tumor necrosis factor α protein levels were significantly depressed by LV-shRNA) of HOTAIR while increased by upregulation of HOTAIR in THP-1 cells. By carrying out bioinformatics analysis, miR-330-5p was predicted as a target of HOTAIR and the correlation between them was validated in our current study. MiR-330-5p was greatly decreased in THP-1 cells incubated with ox-LDL and overexpression of miR-330-5p was able to inhibit oxidative stress and inflammation process. Taken together, it was implied that HOTAIR contributed to atherosclerosis development by downregulating miR-330-5p in human macrophages.

Spatial distribution of rare earth elements and their impact factors in an area with a high abundance of regolith-hosted deposits.

Despite the widespread occurrence of regolith-hosted rare earth elements (REEs) across South China, their spatial distribution characteristics in soils and their impact factors remain largely uncertain. This knowledge gap impedes the exploration of regolith-hosted REE deposits and the assessment of the environmental risks associated with REEs. To address this issue, 180 soil samples were collected from Meizhou City, Guangdong Province, a region known for its high abundance of regolith-hosted REEs. Subsequently, the correlations between REE enrichment/fractionation and various factors, i.e., topography, climate conditions, land use, and landform were analysed using the geo-detector method. The results revealed a highly uneven spatial distribution of REEs and their fractionation features with some regions displaying distinct spatial patterns. Elevation was the dominant factor influencing this distribution, and showed strong correlations with the concentrations of REEs, light REEs (LREEs) and heavy REEs (HREEs); the LREE/HREE ratio; and the positive Ce anomaly (δCe). The negative Eu anomaly (δEu) showed a good correlation with rock type. The enrichment and fractionation of REEs indicated a coupling among the abovementioned factors. For REE enrichment, areas with elevations of 138-148 m, precipitation levels of 1553-1574 mm, annual average land surface temperatures of 30.4-30.5 °C, leaf area index values of 22-29 and surface cutting degree of 21.5-29.9 m showed the highest average abundance within each type (scope) of the predominant factors. These findings highlight the key factors affecting REE distribution, thereby aiding the efficient utilization of regolith-hosted REE resources and the evaluation of their environmental risks.

The combined transduction of copper, zinc-superoxide dismutase and catalase mediated by cell-penetrating peptide, PEP-1, to protect myocardium from ischemia-reperfusion injury.

BACKGROUND: Our previous studies indicate that either PEP-1-superoxide dismutase 1 (SOD1) or PEP-1-catalase (CAT) fusion proteins protects myocardium from ischemia-reperfusion-induced injury in rats. The aim of this study is to explore whether combined use of PEP-1-SOD1 and PEP-1-CAT enhances their protective effects. METHODS: SOD1, PEP-1-SOD1, CAT or PEP-1-CAT fusion proteins were prepared and purified by genetic engineering. In vitro and in vivo effects of these proteins on cell apoptosis and the protection of myocardium after ischemia-reperfusion injury were measured. Embryo cardiac myocyte H9c2 cells were used for the in vitro studies. In vitro cellular injury was determined by the expression of lactate dehydrogenase (LDH). Cell apoptosis was quantitatively assessed with Annexin V and PI double staining by Flow cytometry. In vivo, rat left anterior descending coronary artery (LAD) was ligated for one hour followed by two hours of reperfusion. Hemodynamics was then measured. Myocardial infarct size was evaluated by TTC staining. Serum levels of myocardial markers, creatine kinase-MB (CK-MB) and cTnT were quantified by ELISA. Bcl-2 and Bax expression in left ventricle myocardium were analyzed by western blot. RESULTS: In vitro, PEP-1-SOD1 or PEP-1-CAT inhibited LDH release and apoptosis rate of H9c2 cells. Combined transduction of PEP-1-SOD1 and PEP-1-CAT, however, further reduced the LDH level and apoptosis rate. In vivo, combined usage of PEP-1-SOD1 and PEP-1-CAT produced a greater effect than individual proteins on the reduction of CK-MB, cTnT, apoptosis rate, lipoxidation end product malondialdehyde, and the infarct size of myocardium. Functionally, the combination of these two proteins further increased left ventricle systolic pressure, but decreased left ventricle end-diastolic pressure. CONCLUSION: This study provided a basis for the treatment or prevention of myocardial ischemia-reperfusion injury with the combined usage of PEP-1-SOD1 and PEP-1-CAT fusion proteins.

Effects of vasoactive drugs on hepatic and intestinal circulation and intestinal barrier in patients with septic shock.

In this study, 60 patients with septic shock were selected over the course of 1 year, and the effects of dopamine and norepinephrine combined with dobutamine on hepatic and intestinal circulation and intestinal barrier in patients with septic shock were studied by comparison between the control group and the experimental group. All patients received mechanical ventilation to maintain breathing at 14 to 20 times/min. The experimental group was treated with vascular active drugs after adequate rehydration, and the control group only received adequate rehydration. There were extremely significant differences (p<0.01) in the total effective rate of each group. There were significant differences in the hemodynamic indexes in each group (p<0.05). There was a significant difference in total 24-hour bile output (p<0.01). There were significant differences in liver function and blood lipid values in patients (p<0.01). There were significant differences in the repair of epithelial injury at 0 hour, 48 hours and 96 hours (p<0.01). There were significant differences in the transmembrane resistance of monolayer cells (p<0.01). The expression differences of three proteins ZO-1, occludin and ß-actin were also significant, among which the three proteins in the control group were weak, while those in groups A and B were strong. The expression of tight junction protein in monolayer cells was weakly positive in expression and strong in other proteins. In conclusion, vasoactive drugs had significant effects on hepatic and intestinal circulation and intestinal barrier in patients with septic shock.

Successful Treatment of Pseudomembranous Colitis with Fecal Microbiota Transplantation - A Case Study on A Patient Rescued by Extracorporeal Cardiopulmonary Resuscitation After Cardiac Arrest.

BACKGROUND Pseudomembranous colitis (PMC) is an opportunistic, nosocomial infection caused by Clostridium difficile. CASE REPORT Here we described a patient who developed PMC during her recovery from cardiac arrest. A 16-year-old female high school student experienced sudden cardiac arrest. Spontaneous circulation was not returned by standard cardiopulmonary resuscitation. After her admission to the emergency unit, her cardiac function and neurologic function were finally resumed by extracorporeal cardiopulmonary resuscitation (ECPR); however, after 14 days, her recovery was complicated with excessive diarrhea and shock. Colonoscopy confirmed the diagnosis of PMC. Metronidazole and vancomycin were immediately administered; however, the treatment did not result in any improvement. Fecal microbiota transplantation was then performed, and after 4 transplantations, her diarrhea was significantly ameliorated. After hospital stay for 135 days, the patient was finally discharged with grade II brain function. She later recovered self-care ability in follow-up. CONCLUSIONS The patient suffered from a long-term gastrointestinal ischemia-hypoxia resulting from cardiac arrest. The use of broad-spectrum antibiotics in the later treatment led to refractory PMC, which was successfully managed by multiple fecal microbiota transplantation.

Serum Human Epididymis Protein 4 Combined with Carbohydrate Antigen 125 for Endometrial Carcinoma Diagnosis: A Meta-Analysis and Systematic Review.

Objective: To evaluate the overall diagnostic value of human epididymis protein 4 (HE4) combined with carbohydrate antigen 125 (CA125) in endometrial carcinoma (EC) based on a meta-analysis of all eligible studies. Methods: The PubMed, Cochrane, Embase, CNKI, VANFUN, and VIP databases were searched by index words to identify eligible studies and also to search for relevant literature sources that had been published by January 2019. Eligible studies included prospective cohort studies or cross-sectional studies. The heterogeneity of the included studies was used to select appropriate effect models to calculate summary weighted sensitivity, specificity, and diagnostic odds ratios (DORs). The summary receiver operational characteristic (SROC) analysis was summarized for the EC. Results: In total, 25 studies that had explored the diagnostic accuracy of HE4 combined with CA125 for EC were included in this meta-analysis. Nine were from English language articles and 16 from Chinese language articles. The global sensitivity and specificity of HE4 combined with CA125 for EC were as follows: 66% (95% CI: 60-72) and 92% (95% CI: 88-95), respectively. The global positive likelihood ratio and global negative likelihood ratio of HE4 combined with CA125 for EC were as follows: 8.03 (95% CI: 5.36-12.04) and 0.37 (95% CI: 0.31-0.44), respectively. The global DOR was19.59 (95% CI: 12.25-31.32) for IL-6. The area under the SROC was high for HE4 combined with CA125 (AUC = 0.86; 95% CI: 0.83-0.89). Conclusion: This study provides a systematic review and meta-analysis of the diagnostic accuracy of HE4 combined with CA125 for EC. The results indicate that HE4 combined with CA125 is highly accurate for the diagnosis of EC.

Quantifying the biophysical effects of forests on local air temperature using a novel three-layered land surface energy balance model.

The well-documented energy balance dynamics within forest ecosystems are poorly implemented in studies of the biophysical effects of forests. This results in limitations to the accurate quantification of forest cooling/warming on local air temperature. Taking into consideration the forest air space, this study proposes a three-layered (canopy, forest air space and soil [CAS]) land surface energy balance model to simulate air temperature within forest spaces (Taf) and subsequently to evaluate its biophysical effects on forest cooling/warming, i.e., the air temperature gradient (∆Ta) between the Taf and air temperature of open spaces (Tao) (∆Ta = Taf - Tao). We test the model using field data for 23 sites across 10 cities worldwide; the model shows satisfactory performance with the test data. High-latitude forests show greater seasonal dynamics of ∆Ta, generating considerable cooling of local air temperatures in warm seasons but minimal cooling or even warming effects during cool seasons, while low-latitude tropical forests always exert cooling effects with less interannual variability. The interannual dynamics of ∆Ta are significantly related to the seasonality of solar geometry and canopy leaf phenology. The differences between forest canopy temperature (Tc) and Tao, which are the two most important terms attributed by the CAS model in impacting Taf, explain a large part of forest cooling and warming (May-July: R2 = 0.35; November-January: R2 = 0.51). The novel CAS model provides a feasible way to represent the energy balance within forest ecosystems and to assess its impacts on local air temperatures globally.

Right ventricle performances with echocardiography and 99mTc myocardial perfusion imaging in pulmonary arterial hypertension patients.

Right heart catheterization is commonly used to measure right ventricle hemodynamic parameters and is the gold standard for pulmonary arterial hypertension diagnosis; however, it is not suitable for patients' long-term follow-up. Non-invasive echocardiography and nuclear medicine have been applied to measure right ventricle anatomy and function, but the guidelines for the usefulness of clinical parameters remain to be established. The goal of this study is to identify reliable clinical parameters of right ventricle function in pulmonary arterial hypertension patients and analyze the relationship of these clinical parameters with the disease severity of pulmonary arterial hypertension. In this study, 23 normal subjects and 23 pulmonary arterial hypertension patients were recruited from January 2015 to March 2016. Pulmonary arterial hypertension patients were classified into moderate and severe pulmonary arterial hypertension groups according to their mean pulmonary arterial pressure levels. All the subjects were subjected to physical examination, chest X-ray, 12-lead electrocardiogram, right heart catheterization, two-dimensional echocardiography, and technetium 99m (99mTc) myocardial perfusion imaging. Compared to normal subjects, the right heart catheterization indexes including right ventricle systolic pressure, right ventricle end diastolic pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, pulmonary vascular resistance, and right ventricle end systolic pressure increased in pulmonary arterial hypertension patients and were correlated with mean pulmonary arterial pressure levels. Echocardiography parameters, including tricuspid regurgitation peak velocity, tricuspid regurgitation pressure gradient, tricuspid annular plane systolic excursion and fractional area, right ventricle-myocardial performance index, were significantly associated with the mean pulmonary arterial pressure levels in pulmonary arterial hypertension patients. Furthermore, myocardial perfusion imaging was not observed in the normal subjects but in pulmonary arterial hypertension patients, especially severe pulmonary arterial hypertension subgroup, and showed potential diagnostic properties for pulmonary arterial hypertension. In conclusion, mean pulmonary arterial pressure levels are correlated with several right heart catheterization and echocardiography markers in pulmonary arterial hypertension patients; echocardiography and 99mTc myocardial perfusion can be used to evaluate right ventricle performance in pulmonary arterial hypertension patients. Impact statement In this study, we analyzed the clinical parameters for evaluating RV function, including right ventricle catheterization (RHC), echocardiography, and technetium 99m (99mTc) myocardial perfusion imaging (MPI) in normal Asian subjects and PAH patients ( n = 23 for each group). Our results demonstrated that six RHC indexes, four echocardiography indexes and MPI index were significantly altered in PAH patients and correlated with the levels of mean pulmonary arterial pressure. Importantly, we evaluated the diagnostic performance of MPI and found that MPI has a strong diagnostic accuracy in PAH patients. The findings from this study will be of interest to clinical investigators who make diagnosis and therapeutic strategies for PAH patients.

Co-expression network analysis of long noncoding RNAs (IncRNAs) and cancer genes revealsSFTA1P and CASC2abnormalities in lung squamous cell carcinoma.

Lung squamous cell carcinoma(LSCC) is the most common and aggressive lung tumor with poor clinical outcome. Previously studies showed that deregulation of long noncoding RNAs (lncRNAs) were involved in LSCC. We intended to figure out the role of lncRNAs in the regulation process of cancer-related genes and pathways they are involved. Data of 552 samples, including 501 cancer samples and 51 normal ones, were extracted from The Cancer Genome Atlas (TCGA). Differentially expressed lncRNAs (DEIs) were screened out (FDR<0.05, |logFC|>1) and then followed by GO ontology and KEGG annotation analysis. Oncogenes from COSMIC data set and Tumor suppressor genes (TSGs) from TSGene data set were collected and analyzed by gene Set Enrichment Analysis (GSEA) . The differentially expressed oncogenes and tumor supressor gene (TSGs) were obtained and co-expression analysis was conducted to generate co-expression lncRNA-gene pairs, which can be helpful in figuring out the role of lncRNA in the regulation of oncogenes and tumor suppressor genes. A total of 31 lncRNAs with low expression levels and 37 lncRNAs with high expression levels were screened out and most of them were enriched in pathways such as meiosis, male gamete generation, defensins. Of note, SFTA1P and CASC2 were found to be related with most of the oncogenes and TSGs by co-expression analysis. We suggested SFTA1P and CASC2 played important role in the regulation of both oncogene and TSGs during the carcinogenesis of LSCC and have the potential to be applied in future diagnosis, prognostic process and target therapy of LSCC.

Residents' Waste Separation Behaviors at the Source: Using SEM with the Theory of Planned Behavior in Guangzhou, China.

Understanding the factors that affect residents' waste separation behaviors helps in constructing effective environmental campaigns for a community. Using the theory of planned behavior (TPB), this study examines factors associated with waste separation behaviors by analyzing responses to questionnaires distributed in Guangzhou, China. Data drawn from 208 of 1000-field questionnaires were used to assess socio-demographic factors and the TPB constructs (i.e., attitudes, subjective norms, perceived behavioral control, intentions, and situational factors). The questionnaire data revealed that attitudes, subjective norms, perceived behavioral control, intentions, and situational factors significantly predicted household waste behaviors in Guangzhou, China. Through a structural equation modeling analysis, we concluded that campaigns targeting moral obligations may be particularly effective for increasing the participation rate in waste separation behaviors.