Variable Stress Research Articles

The Effect of Work Stress on Work Deviant Behavior Case Study: CV. Madinna Dome Ambassador through Job Satisfaction as an Intervening Variable

Research Aims: This study aims to analyze the effect of work stress on work deviant behavior case studies in CV. Duta Madinna Kubah through Job Satisfaction as an intervening variable.
 Methodology: This study used a sample of 95 respondents who were determined by the sampling technique with the census method. In this study, using data analysis techniques, namely Path Analysis (path analysis). The analytical tool used in this study using SPSS software.
 Research Findings: The results of this study indicate that the variable job stress has a significant negative effect on job satisfaction, job satisfaction has a negative and significant effect on work deviant behavior, job stress has a significant positive effect on work deviant behavior, job stress has a significant effect on work deviant behavior, which is mediated by the variable job satisfaction.
 Theoretical Contribution: This research advances theoretical understanding by revealing the complex interaction among work stress, job satisfaction, and deviant work behavior, providing valuable insights for academics and practitioners in the field of organizational psychology and management.
 Implication: Organizations can implement training programs to equip employees and managers with effective stress management strategies. Additionally, organizational development efforts can include initiatives to enhance job satisfaction and foster a positive work culture.

Pengaruh Keseimbangan Kehidupan Kerja terhadap Kinerja Auditor dengan Stres Kerja Sebagai Variabel Mediasi

This research was conducted to determine and analyze the influence of work-life balance through the mediating variable work stress on the performance of BPK auditors representing West Kalimantan Province. The research respondents were 30 auditors who held the positions of first expert examiner and junior expert examiner. Data collection was carried out through an online questionnaire by providing an assessment of work-life balance indicators, testing work stress as a mediation and measuring its impact on the performance of BPK auditors. The data obtained was then analyzed using SmartPLS version 4 software. The results showed that work-life balance had no significant effect on auditor performance, work-life balance had a significant effect on auditor work stress, work stress had a significant effect on auditor performance and work-life balance had a significant effect on auditor performance through the mediating role of work stress.

Effect of lithofacies assemblages on multi-scale fractures in the transitional shale and its implications for shale gas exploration

Shale gas exploration and development have significant potential in the Upper Permian Longtan formation. Muti-scale fracture characteristics and its controlling factors of transitional shale reservoirs within the complex lithofacies combination are still not sufficiently understood. The fracture characteristics of Longtan Formation shale were conducted by using cores, thin sections, and SEM. On this basis, the controlling factors of fractures and their impact on gas properties were analyzed using XRD analysis, TOC, N2 adsorption, breakthrough pressure experiment and two-dimensional finite element simulation. The results indicate natural fractures above the micron scale are mainly tectonic fractures. Tectonic fractures are high-angle shear, parallel slip, and near-vertical tensional fractures; while non-tectonic fractures mainly are bedding fractures; and there are numerous interlayer, intraparticle and interparticle micro-fractures at the nano scale. The density and extent of fractures in the same structural setting are primarily influenced by lithofacies and rock mechanical properties. Fractures are well developed in organic-poor calcareous and organic-containing siliceous lithofacies because of relatively more brittle minerals. However, 50% and 45%, respectively, are the threshold for the effects of brittle and clay minerals on the density of micro-fractures. The development of micro-fractures increases with these minerals under the content threshold. While beyond this threshold value, micro-fractures development are significantly constrained. The lithology assembles greatly influenced the characteristics of fractures because of variable stress barrier and rock mechanical properties. The fractures of shale interbedded with sandstone with the lower deviation are more developed and much longer than those of shale interbedded with coal and limestone. Micro-fractures can considerably contribute to the enrichment of shale gas, which will enhance the amount of gas that can be stored. However, intense construction of macro-fractures with high dip-angle leads to loss of sealing ability in the floor or roof. Our research establishes a foundation for the analysis of transitional shale fractures in the Longtan formation or other regions, which helps to reduce the risk of exploration and development.

Отражение звука от упругой конечной цилиндрической оболочки различной относительной длины

A calculation of the sound pressure frequency dependences scattered by a finite elastic cylindrical shell placed in a liquid medium is presented. The shell has hemispherical ends and is considered either hollow or filled with gas or liquid. The scattered sound pressure under conditions of hydroelastic contact on the shell surfaces is found by jointly using the Kirchhoff integral and the integral equation for the elastic medium displacement vector, obeying the Lamé equation. Boundary conditions regarding stresses and displacements are formulated for each of the shell contact surfaces with the external and internal environments. Considerating approach is based on the numerical transformation of continuous integral equations into a system of linear algebraic equations using curvilinear isoparametric boundary elements. In this case, the elements geometry and the main variables (displacements and stresses) are specified using the same interpolating relations (shape functions). The scattered sound pressure frequency dependences are calculated and analyzed for various ratios of the length and shell diameter.

Linking stress with urocortin in rats.

The corticotropin-releasing factor neuropeptides (CRH and UCN-1,2,3), as well as spexin, contribute to the control of energy balance and limit food intake in mammals. However, the role of these neuropeptides in chronic variable stress remains unknown. The effect of chronic varied stress on circulating corticosterone levels and urocortin expression levels in the brains of experimental rats was studied in this study. Rats were subjected with 28 days long term stress protocol, end of stress protocol experimental and control animal organs isolated, brain urocorcortin-1,2,3 expression by RT-PCR and serum corticosterone by ELISA method. UCN levels in the brain were altered in rats subjected to prolonged varied stress. Furthermore, corticosterone levels were elevated as a result of the same urocortin expression pattern, indicating that urocortin expression is controlled by glucocorticoids via a glucocorticoid-responsive element (GRE). Thus, data shows that hypothalamus-pituitary-adrenal (HPA) axis, also known as the LHPA axis, and limbic system are both stimulated by stress, which is reflected in the form of elevated corticosterone levels, according to the genes UCN1, 2, and 3.

A Fractional-Order Creep Model of Water-Immersed Coal

The long-term stability of a coal pillar dam is a serious concern for coal mine underground reservoirs because of the creep behavior of coal in complex water immersion and mechanical environments. In order to investigate the characteristics of creep deformation of water-immersed coal and develop a proper creep model, this paper implemented a series of creep experiments of coal via multistage loading at various water-immersion times. The experiment data were analyzed, in terms of immersion-induced damage, elasto-plastic performance, creep behavior, etc., suggesting obvious mechanical properties’ degradation of coal by water. The elastic modulus and peak strength of water-immersed coal decrease exponentially with the immersion time, while the creep rate of coal shows an upward tendency with the promoted immersion time. According to the remarked relationships of elastic, viscoelastic, and viscoplastic properties versus the stress levels and water-immersion time, a creep model based on conformable fractional derivatives is proposed, considering the influence of the water-immersion time and variable stress level. The proposed model was verified using the experiment data, showing a good capacity of the creep model for reproducing the creep process of water-immersed coal. This paper provides a fundamental model for further studying the stability of coal pillars and their influence on the safety of underground water reservoirs.

Pengaruh Stress Kerja Terhadap Turnover Intention Karyawan Pada PT. Central Mega Kencana di Jakarta

This study aims to determine the effect of work stress on employee turnover intention at PT. Central Mega Kencana in Jakarta. The research method used is quantitative. The sample in this study were employees of PT. Central Mega Kencana in Jakarta, whose number was determined using the slovin formula and obtained representative results totaling 95 people. The sampling method in this study uses probability sampling with simple random sampling technique. The data analysis technique in this study used simple linear regression with the statistical program SPSS version 24. The results showed that the variable work stress has a significant effect on employee turnover intention at PT. Central Mega Kencana in Jakarta, this is evident from the results of the hypothesis test between work stress on employee performance employee turnover intention at PT. Central Mega Kencana obtained tcount > ttable (13.675 > 1.986) (H1 accepted). Based on the results of the analysis of the coefficient of determination, a result of 66.8% is obtained, which means that the contribution of work stress contributes to the variable turnover intention of employees of PT. Central Mega Kencana amounted to 66.8, the remaining 33.2% was influenced by other factors

Classification of Tropical Forage Grass Varieties Under Moderate and Severe Water Stress using Naïve Bayes and Kernel Density Estimation

The selection of forage grasses that are more adapted to adverse conditions, such as water scarcity or dry rain periods, is extremely important. Mainly due to the severe climate changes, and the search for more sustainable ways of farming. Forage grasses form the basis of the diet of beef cattle and are also used as a source of biofuels, for erosion control and soil improvement. This work presents a machine learning methodology to obtain classification models for nine forage cultivars, subject to moderate and severe water stress. The Naïve Bayes algorithm is used together with the Kernel Density Estimation method to obtain the densities used in the classification models. Before learning the models, the grouped cross-validation technique and also the grid search are used to search for the best set of hyperparameters. The best accuracy and precision results are 0.88 and 0.90, respectively. It is observed that the classification performance depends on the cultivars used in the training and test sets. At the end, the estimated probability densities are also analyzed by comparing them with some statistics obtained for each variable and water stress or control environments.

Analysis of effects of material anisotropy on ductile damage using microscopic unit‐cell model

AbstractIt is experimentally observed that the failure in ductile metals is mainly due to the nucleation, growth, and coalescence of micro‐voids as well as micro‐shear‐cracks. Furthermore, plastic anisotropy has significant role in damage and failure behavior of ductile metals. Finite element simulations of unit cell provide a basis to understand different mechanisms on micro‐scale, for example, changes in shape and size of single voids and defects as well as localization of plastic strains. This contribution deals with the numerical analysis of unit cell containing spherical void subjected to symmetrical boundary conditions taking material anisotropy into account. Elastic isotropic behavior is described by Hooke's law while Hoffman yield criterion considering the strength‐differential effect is used to model the anisotropic plastic behavior. Generalized anisotropic stress invariants, generalized stress triaxiality, and generalized Lode parameter are introduced to characterize the stress state in the anisotropic ductile metal. The effect of plastic anisotropy on the damage behavior of the aluminum alloy EN AW‐2017A is studied in detail by performing a series of numerical simulations covering a wide range of stress triaxialites and Lode parameters. Stress triaxility and Lode parameter are controlled and kept constant during the entire loading process. The numerical results are then used to discuss general mechanisms of damage and failure process in ductile metals.

Sleep, brain systems, and persistent stress in early adolescents during COVID-19: Insights from the ABCD study

PurposeThe first year of the COVID-19 pandemic constituted a major life stress event for many adolescents, associated with disrupted school, behaviors, social networks, and health concerns. However, pandemic-related stress was not equivalent for everyone and could have been influenced by pre-pandemic factors including brain structure and sleep, which both undergo substantial development during adolescence. Here, we analyzed clusters of perceived stress levels across the pandemic and determined developmentally relevant pre-pandemic risk factors in brain structure and sleep of persistently high stress during the first year of the COVID-19 pandemic. MethodsWe investigated longitudinal changes in perceived stress at six timepoints across the first year of the pandemic (May 2020–March 2021) in 5559 adolescents (50 % female; age range: 11–14 years) in the United States (U.S.) participating in the Adolescent Brain Cognitive Development (ABCD) study. In 3141 of these adolescents, we fitted machine learning models to identify the most important pre-pandemic predictors from structural MRI brain measures and self-reported sleep data that were associated with persistently high stress across the first year of the pandemic. ResultsPatterns of perceived stress levels varied across the pandemic, with 5 % reporting persistently high stress. Our classifiers accurately detected persistently high stress (AUC > 0.7). Pre-pandemic brain structure, specifically cortical volume in temporal regions, and cortical thickness in multiple parietal and occipital regions, predicted persistent stress. Pre-pandemic sleep difficulties and short sleep duration were also strong predictors of persistent stress, along with more advanced pubertal stage. ConclusionsAdolescents showed variable stress responses during the first year of the COVID-19 pandemic, and some reported persistently high stress across the whole first year. Vulnerability to persistent stress was evident in several brain structural and self-reported sleep measures, collected before the pandemic, suggesting the relevance of other pre-existing individual factors beyond pandemic-related factors, for persistently high stress responses.

Static axial tension or compression stress effects on shear cracks initiating under cyclic torsion loads in multiaxial fatigue tests

This work proposes models that can better fit and explain apparently contradictory mean stress effects observed when superimposing axial tension or compression loads on cyclic torsion fatigue tests. It introduces new shear-based multiaxial fatigue damage models, modifying the classic Fatemi-Socie equation to consider the peak deviatoric stress normal to the initiating shear crack as the actual driving force for the peak or mean effects of the normal stresses. This deviatoric hypothesis can quantify the odd detrimental effects of static axial compression observed on axial shear cracks tested under cyclic torsion. Additionally, applying the peak deviatoric correction term only to the elastic component of the shear strain range allows an even better description of the increasing mean normal stress effects in high-cycle fatigue, eliminating the need for a variable normal stress sensitivity coefficient in the multiaxial fatigue damage parameter. To evaluate the proposed shear-based models, their life and crack initiation direction predictions are compared for cyclic torsion experiments both with and without superimposed static axial stresses for steels and aluminum alloys, including both literature and original data. The experiments show that axial compression can be detrimental to fatigue crack initiation lives, depending on the cracking mode and on the presence of bifurcations, which effects could be explained from the proposed deviatoric damage parameters.

Assessment of Window Size and Layout Impact on a View Quality Perception in a Virtual Reality Environment

ABSTRACT Window views are key factors that affect buildings’ occupants psychological and physiological comfort and wellbeing. Window design should consider the holistic impacts on building energy, lighting performance, and the connection to the outdoors provided by the view which is usually overlooked. In this study, view perception, stress recovery, physiological, and psychological affect were evaluated in virtual environments of five different conditions varying the physical dimensions of a window located in the same office space with an urban view. This allowed three window-to-wall ratios (i.e. 10%, 20%, and 30%) and two different window layouts (i.e. narrow and wide) to be compared. Twenty-five participants were recruited. Subjective self-assessments on view perception (e.g. content and complexity), self-assessment and physiological measures (e.g. skin conductance and heart rate variability) stress recovery besides psychological affect were measured. Participants performed a Stroop-test to induce stress that was immediately followed by a period of recovery facilitated by exposure to one of the five window conditions. Results showed that increased window size advocated higher view perception assessments, increased stress recovery, and positive psychological affect. Measurements of skin conductance and heart rate variability also corroborated these findings. Differences in window layout were also revealed, but only for 10% WWRs. Therefore, WWR is not a reliable indicator for view perception for small window sizes, indicating that layout preference is dependent on window size. This study highlights the importance of considering view perception for occupant health and wellbeing when sizing window openings, since these may not necessarily align with other design criteria.

Multifarious Plant Growth-Promoting Rhizobacterium Enterobacter sp. CM94-Mediated Systemic Tolerance and Growth Promotion of Chickpea (Cicer arietinum L.) under Salinity Stress.

Chickpea is one of the most important leguminous crops and its productivity is significantly affected by salinity stress. The use of ecofriendly, salt-tolerant, plant growth-promoting rhizobacteria (PGPR) as a bioinoculant can be very effective in mitigating salinity stress in crop plants. In the present study, we explored, characterized, and evaluated a potential PGPR isolate for improving chickpea growth under salt stress. A potential PGPR was isolated from rhizospheric soils of chickpea plants grown in the salt-affected area of eastern Uttar Pradesh, India. The isolate was screened for salt tolerance and characterized for its metabolic potential and different plant growth-promoting attributes. Further, the potential of the isolate to promote chickpea growth under different salt concentrations was determined by a greenhouse experiment. A rhizobacteria isolate, CM94, which could tolerate a NaCl concentration of up to 8% was selected for this study. Based on the BIOLOG carbon source utilization, isolate CM94 was metabolically versatile and able to produce multiple plant growth-promoting attributes, such as indole acetic acid, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophore, hydrogen cyanide (HCN), and ammonia as well as solubilized phosphate. A polyphasic approach involving the analysis of fatty acid methyl ester (FAME) and 16S rRNA gene sequencing confirmed the identity of the isolate as Enterobacter sp. The results of greenhouse experiments revealed that isolate CM94 inoculation significantly enhanced the shoot length, root length, and fresh and dry weight of chickpea plants, under variable salinity stress. In addition, inoculation improved the chlorophyll, proline, sugar, and protein content in the tissues of the plant, while lowering lipid peroxidation. Furthermore, isolate CM94 reduced oxidative stress by enhancing the enzymatic activities of superoxide dismutase, catalase, and peroxidase compared to in the respective uninoculated plants. Overall, the results suggested that using Enterobacter sp. CM94 could significantly mitigate salinity stress and enhance chickpea growth under saline conditions. Such studies will be helpful in identifying efficient microorganisms to alleviate salinity stress, which in turn will help, to devise ecofriendly microbial technologies.

Battery Earth: using the subsurface at Boulby underground laboratory to investigate energy storage technologies

Renewable energy provides a low-carbon alternative to power generation in the UK. However, the resultant supply varies on daily, weekly and seasonal cycles, such that for green energies to be fully exploited new grid-scale energy storage systems must be implemented. Two pilot facilities in Germany and the United States have demonstrated the potential of the Earth as a battery to store compressed air, using off-peak surplus energy. Natural accumulations of salt (halite deposits) in the UK represent a large and untapped natural storage reservoir for compressed air with the ability to provide instantaneous green energy to meet peak demand. To realise the potential of this emerging technology, a detailed knowledge of the relationship between mechanics, chemistry and geological properties is required to optimise cavern design, storage potential and economic feasibility. The variable stresses imposed on the rock matrix by gas storage, combined with the cyclic nature of cavern pressurisation are barriers to deployment that need to be addressed to enable large-scale adoption of schemes. Well-designed field experiments are a lynchpin for advancing research in this area, especially when supported by state-of-the-art characterisation and modelling techniques. The research facility at STFC’s Boulby Underground Laboratory presents the ideal location to tackle these fundamental issues to optimise “Battery Earth”.

Fighting Against Aging-Related Dysfunction Under Variable Stress: Possible Antioxidant and Neuroprotective Roles of Metformin via Increased Superoxide Dismutase and Brain-Derived Neurotrophic Factor

Background: Chronic stress causes a deleterious impact on older adults and accelerates the aging process through different mechanisms, such as increased oxidative stress. Metformin, a drug with pleiotropic effects, exhibited neuroprotective and antioxidant properties. Objectives: Our study aimed to investigate the metformin effects on aging under stress conditions. Methods: Old male rats (18 months) were divided into 6 experimental groups (N = 8): 1 = control; 2 and 3 = metformin (1 or 10 mg/kg, orally, 40 days); 4 = stress (40 days); 5 and 6 = stress + metformin (1 or 10 mg/kg, orally, 40 days). Chronic variable stress was induced with 7 types of stressors for 40 days. Neurobehavioral functions were evaluated using the Morris water maze, Y-maze, elevated plus maze, open field, forced swimming test, rotarod, and exhausting swimming test. In addition, BDNF level and SOD activity were measured. Results: Stress induction increased memory deficits, anxiety, depression, and muscle fatigue in old rats. Metformin (10 mg/kg) enhanced memory performance and muscle strength and diminished anxiety and depression in stressed animals (P < 0.05). Treatment with metformin increased the BDNF brain level and SOD activity (P < 0.05). Conclusions: Metformin restored neurobehavioral disruptive changes induced by chronic stress in old rats. The underlying mechanisms could be related to the prevention of oxidative stress and neuronal damage and elevation of BDNF levels in the brain.

Predicting Swell in Clay-Sand Mixtures Used in Liners

A method to predict the swellability of clay-sand mixtures is proposed. This model is a modified form of the Studds (1997) prediction model for clay-sand mixtures. The new proposed model uses the laboratory fall cone penetration technique to produce a characterization chart. This chart presents slope levels that can be used to obtain an equation for the final clay void ratio versus the vertical effective stress for clays. The porosity of the clay-sand mixtures was worked out based on a correction factor obtained from compression and porosity measurements in the laboratory. The porosity of the mixture was merged into the clay profile equation to compute the final clay void ratio at a specified stress level, which made it possible to predict the swelling behavior for different and variable stress levels. The swellability slope was obtained using fall cone tests conducted on the fine portion. Mixtures of kaolinite and bentonite were introduced to represent soils with different swell potentials. The fall cone measurements of a few points can be used to establish the swellability relationships for natural clay. Merging fall cone points with the swellability slope chart can define the profile of the vertical effective stress versus the clay void ratio.

THU118 Prefrontal-Medullary Circuit Is Necessary For Chronic Stress-Induced Neuroendocrine And Behavioral Outcomes

Abstract Disclosure: S.A. Pace: None. E. Lukinic: None. P. Barrette: None. T. Wallace: None. B. Myers: None. Chronic stress exposure is a major risk factor for psychiatric and cardiometabolic diseases. Although the pathologies associated with chronic stress are well-documented, the biological mechanisms underlying these physiological changes remain unknown. Human imaging studies indicate the prefrontal cortex is a key site for processing stress-related information. Within the rat prefrontal cortex, the infralimbic area (IL) is critical for regulating physiological stress reactivity in a sex-specific fashion. Here we examined the necessity of an IL downstream circuit for neurogenic regulation of neuroendocrine susceptibility after chronic stress. We focused on an IL to rostral ventrolateral medulla (RVLM) circuit due to the ability of the RVLM to initiate the sympatho-adrenomedullary stress responses and influence HPA axis activity. Critically, the IL-RVLM circuit is structurally positioned to underlie a crucial link between stress appraisal and sympathetic reactivity. To determine the role of the IL-RVLM circuit during chronic stress, an intersectional viral strategy was used to express a light-chain variant of Tetanus Toxin (TeLC) in RVLM-projecting IL neurons, thereby disrupting IL-RVLM signaling. TeLC-expressing IL neurons had less synaptobrevin-2 protein located on terminals and fewer synaptic appositions in the RVLM. This chronic circuit disruption approach was evaluated in the context of a 2-week chronic variable stress (CVS) paradigm in male and female rats. In males, CVS-exposed TeLC rats displayed decreased corticosterone levels in response to a novel stressor compared to control rats. CVS-naïve males showed no significant changes. In females, we similarly observed no differences in unstressed rats. However, CVS TeLC female rats had increased glycemic and corticosterone stress responses compared to CVS control animals. Additionally, female CVS TeLC rats had increased behavioral avoidance indicated by less time spent in the center of an open field arena compared to CVS control rats. This behavioral effect was not present in males. These results suggest that the IL-RVLM circuit is essential for preventing chronic stress outcomes in female rats, but not males. Further, this circuit regulation is necessary only after chronic stress exposure. Future studies will be aimed at determining sex differences in chronic stress effects on IL-RVLM signaling. Presentation: Thursday, June 15, 2023

Characterizing genetic variation in the regulation of the ER stress response through computational and cis-eQTL analyses.

Misfolded proteins in the endoplasmic reticulum (ER) elicit the ER stress response, a large transcriptional response driven by 3 well-characterized transcription factors (TFs). This transcriptional response is variable across different genetic backgrounds. One mechanism in which genetic variation can lead to transcriptional variability in the ER stress response is through altered binding and activity of the 3 main TFs: XBP1, ATF6, and ATF4. This work attempts to better understand this mechanism by first creating a computational pipeline to identify potential binding sites throughout the human genome. We utilized GTEx data sets to identify cis-eQTLs that fall within predicted TF binding sites (TFBSs). We also utilized the ClinVar database to compare the number of pathogenic vs benign variants at different positions of the binding motifs. Finally, we performed a cis-eQTL analysis on human cell lines experiencing ER stress to identify cis-eQTLs that regulate the variable ER stress response. The majority of these cis-eQTLs are unique to a given condition: control or ER stress. Some of these stress-specific cis-eQTLs fall within putative binding sites of the 3 main ER stress response TFs, providing a potential mechanism by which these cis-eQTLs might be impacting gene expression under ER stress conditions through altered TF binding. This study represents the first cis-eQTL analysis on human samples experiencing ER stress and is a vital step toward identifying the genetic components responsible for the variable ER stress response.

Juvenile variable stress modulates, in female but not in male Wistar rats, ethanol intake in adulthood

Early stress can increase vulnerability to psychopathological disorders, including substance use disorders. The effects of stress in the juvenile period of the rat, that extends between weaning and the onset of adolescence (equivalent to late human childhood), have received little attention. This study assessed short and long-term behavioral effects of juvenile stress, with a focus on effects on ethanol intake. Male and female Wistar rats were exposed to variable stress (restraint, elevated platform, forced swimming, and social instability) or to restraint stress only, between postnatal days 26 to 29 (PDs 26–29). During adolescence, patterns of anxiety (PD 31) and depression (PD 33), ethanol intake (PDs 36–45) and behavioral sensitivity to the effects of acute stress (PD 47) were evaluated. In adulthood, alcohol ingestion was assessed through two-bottle ethanol intake tests (PDs 75–85). An additional experiment measured blood ethanol levels after a limited access intake session in adolescence. Exposure to juvenile variable stress exerted very mild effects in adolescence, but reduced ethanol ingestion in adulthood, in females only. Ethanol intake during the limited access session was significantly correlated to blood alcohol levels. The results indicate that a schedule of juvenile variable stress that did not significantly alter anxiety-related behaviors induced, nonetheless, sexually dimorphic effects on ethanol intake in adulthood. Early stress exposure that reduced alcohol intake in Wistar rats has been associated with changes on brain opioid and dopamine receptors. These results highlight the impact of early stress exposure on adult female ethanol consumption and its possible underlying neurobiological changes, involving opioid and dopamine receptors.

A 3D objective material model for elastic–plastic damage behavior of fiber reinforced polymer composites

To simulate the plastic deformation and the progressive failure process of fiber reinforced polymer composites under 3D stress conditions, a new elastic–plastic damage model is proposed to satisfy the objectivity of 3D stress conditions. A new two-parameter 3D plasticity criterion and a simple non-associated flow potential, expressed by stress invariants of a transversely isotropic unidirectional (UD) lamina, are developed to characterize plastic deformation in an objective way. Moreover, the material degradation model and damage evolution laws are constructed on a matrix fracture angle-dependent coordinate system to ensure the objectivity of the continuum damage mechanics (CDM) approach. In addition, a new linear law alleviating mesh dependence is derived to govern the damage variable evolution in the elastic–plastic damage process. ​The effectiveness and objectivity of the proposed material model are demonstrated by a series of test cases.