Development Of Stress Symptoms Research Articles

Arabidopsis thaliana transcription factors MYB28 and MYB29 shape ammonium stress responses by regulating Fe homeostasis.

Although ammonium (NH4+ ) is a key intermediate of plant nitrogen metabolism, high concentrations of NH4+ in the soil provoke physiological disorders that lead to the development of stress symptoms. Ammonium nutrition was shown to induce the accumulation of glucosinolates (GSLs) in leaves of different Brassicaceae species. To further understand the link between ammonium nutrition and GSLs, we analysed the ammonium stress response of Arabidopsis mutants impaired in GSL metabolic pathway. We showed that the MYB28 and MYB29 double mutant (myb28myb29), which is almost deprived of aliphatic GSLs, is highly hypersensitive to ammonium nutrition. Moreover, we evidenced that the stress symptoms developed were not a consequence of the lack of aliphatic GSLs. Transcriptomic analysis highlighted the induction of an iron (Fe) deficiency response in myb28myb29 under ammonium nutrition. Consistently, ammonium-grown myb28myb29 plants showed altered Fe accumulation and homeostasis. Interestingly, we showed overall that growing Arabidopsis with increased Fe availability relieved ammonium stress symptoms and that this was associated with MYB28 and MYB29 expression. Taken together, our data indicated that the control of Fe homeostasis was crucial for the Arabidopsis response to ammonium nutrition and evidenced that MYB28 and MYB29 play a role in this control.

Antagonistic shifting from abscisic acid- to salicylic acid-mediated sucrose accumulation contributes to drought tolerance in Brassica napus

The phytohormone salicylic acid (SA), as an important signaling molecule involved in the regulation of plant stress responses. This study aimed to characterize the hormonal regulation of drought-responsive sugar metabolism, focusing on SA-mediated sucrose modulation with regard to the drought resistance mechanism. The responses of sucrose synthesis, starch degradation, sucrose transport, as well as stress symptom development to SA pretreatment and/or drought imposition were interpreted in relation to the altered endogenous hormonal status and their signaling genes. Drought-induced severe reduction of leaf biomass coincided with the highest endogenous level of abscisic acid (ABA) and expression of SAG12. Under drought-stressed, sugar accumulation was mainly due to the enhanced hexose level with depressed expression of hexokinase gene HXK1 and, in part, to increased sucrose content with the highest expression of ABA-dependent sucrose signaling genes SnRK2.2 and AREB2. In the presence of SA, an additional sucrose accumulation occurred with further enhancement of sucrose phosphate synthase (SPS) activity and starch degradation-related genes BAM1 and AMY3 expression, which coincided with the depression of SnRK2.2 and AREB2. Further, SA-mediated sucrose accumulation was responsible for the induction of phloem sucrose loading with enhanced expression of sucrose transporter genes SUT1 and SUT4. SA-mediated pathogenesis-related protein 2 (PR2) activation reflected a synergistic interaction between SA and sucrose signaling. These results indicate that antagonistic shifting from ABA- to SA-mediated sucrose accumulation is an important process in regulating osmotic potential and leaf senescence.

P.4.13 Exploring neurocognitive mechanisms underlying losartan-augmented prevention of posttraumatic stress symptom development

In recent years, most U.S. states have passed autism mandates requiring private insurers to cover autism spectrum disorders (ASD). Little is known about the post-mandate changes in healthcare expenditures.This study utilized 2006–2012 de-identified insurance claims data from the largest private insurer in Pennsylvania (PA), where the mandate went into effect in mid 2009. Healthcare expenditures were defined as the amount the insurer paid for healthcare services and were adjusted to 2012 price level. A mixed effects model was used to analyze the expenditures.A total of 9471 children with ASD were included. Although the pre-mandate total expenditures per child with ASD were similar, the post-mandate expenditures significantly increased for groups subject to the autism mandate (87% increase from $7754 in 2008 to $14,486 in 2010) compared to the exempt groups (27% increase from $7238 to $9171). By insurance type, the change from 2008 to 2010 in ASD-related expenditures per child with ASD was $8439 for fully insured large employer sponsored plans and $43 for the Children’s Health Insurance Program (CHIP), both subject to the PA mandate; and $2631 for the self-insured, $980 for small-employers, and $-92 for individual plans, all of which are exempt from the mandate. These increases were due to outpatient services but not inpatient or drug costs.Healthcare expenditures increased significantly following the PA autism mandate. Nonexempt, large employer groups had the largest increase in spending. Some exempt, self-insured companies may have voluntarily covered ASD services, leading to a moderate increase.

Genes known to escape X chromosome inactivation predict co-morbid chronic musculoskeletal pain and posttraumatic stress symptom development in women following trauma exposure.

Co-morbid chronic musculoskeletal pain (CMSP) and posttraumatic stress symptoms (PTSS) are frequent sequelae of motor vehicle collision, are associated with greater disability than either outcome alone, and are more prevalent in women than men. In the current study we assessed for evidence that gene transcripts originating from the X chromosome contribute to sex differences in vulnerability to CMSP and PTSS after motor vehicle collision. Nested samples were drawn from a longitudinal study of African American individuals, and CMSP (0-10 numeric rating scale) and PTSS (impact of events scale, revised) outcomes were assessed 6 months following motor vehicle collision. Blood RNA were sequenced (n = 101) and the relationship between X chromosome mRNA expression levels and co-morbid CMSP and PTSS outcomes was evaluated using logistic regression analyses. A disproportionate number of peritraumatic X chromosome mRNA predicting CMSP and PTSS in women were genes previously found to escape X chromosome inactivation (11/40, z = -2.9, p = .004). Secondary analyses assessing gene ontology relationships between these genes identified an enrichment in genes known to influence neuronal plasticity. Further, the relationship of expression of two critical regulators of X chromosome inactivation, X-inactive specific transcript (XIST) and Yin Yang 1 (YY1), was different in women developing CMSP and PTSS. Together, these data suggest that X chromosome genes that escape inactivation may contribute to sex differences in vulnerability to CMSP and PTSS after motor vehicle collision.

Post-traumatic stress symptom development as a function of changing witnessing in-home violence and changing peer relationship quality: Evaluating protective effects of peer relationship quality

In the present study, witnessing in-home violence and peer relationship quality are evaluated as to their relative impact on Post Traumatic Stress (PTS) symptoms among children aged 8 to 17 investigated by child protective services (CPS) for maltreatment exposure. The sample included 2151 children from the National Survey of Child and Adolescent Well-Being II (NSCAW II). Linear growth models were estimated to assess associations between changes in PTS symptoms, witnessing in-home violence, and peer relationship quality over time. Greater frequency of witnessing in-home violence at baseline (i.e. wave 1) was associated with higher baseline PTS symptoms (β = 0.44). Increases in witnessing in-home violence frequency over time (average annual change across three years) had a strong association with increases in PTS symptoms over time (β = 0.88). Baseline peer relationship quality was associated with fewer PTS symptoms at baseline (β = −0.45). Increases in peer relationship quality over time were strongly associated with declines in PTS symptoms over time (β = −0.68). Peer relationship quality at baseline did not moderate baseline or over time associations between witnessing in-home violence and PTS symptoms. The average decline in PTS symptoms due to decreases in witnessing in-home violence and increases in peer relationship quality was 0.51 and 0.65 standard deviations respectively, over the three-year study period. Reducing chronic witnessing in-home violence and promoting the development of healthy social relationships with peers are critical for PTS symptom recovery.

Sense of Threat as a Mediator of Peritraumatic Stress Symptom Development During Wartime: An Experience Sampling Study.

Exposure and sense of threat have been associated with stress symptoms, yet these relationships have not been clarified during the peritraumatic period. We investigated the mediating role of sense of threat in the link between exposure to rocket warning sirens and stress symptoms during wartime, and the effect of severe mental illness (SMI) status and gender on this mediation. A 30-day twice-daily smartphone-based intensive assessment of exposure to sirens, sense of threat, and peritraumatic stress symptoms was performed during the 2014 Israel-Gaza conflict. Participants included 182 highly exposed individuals with or without SMI. Multilevel structural equation modeling analysis was performed, with SMI status and gender as confounders. Exposure affected the level of peritraumatic stress symptoms both directly, b = 1.07, p < .001, 95% CI [0.32, 1.82], and indirectly, b = 0.78, p < .001, 95% CI [0.24, 1.33], through sense of threat. The effect of sense of threat on stress symptoms was larger in the SMI group, b = 0.86, p < .001, 95% CI [0.31, 1.40]. Gender did not have a significant effect. Sense of threat has a key role in symptom development during the peritraumatic timeframe. Intervention and prevention efforts should start early and focus on promoting a sense of safety, particularly with people with SMI.

Neural indicators of interpersonal anger as cause and consequence of combat training stress symptoms.

Angry outbursts are an important feature of various stress-related disorders, and commonly lead to aggression towards other people. Findings regarding interpersonal anger have linked the ventromedial prefrontal cortex (vmPFC) to anger regulation and the locus coeruleus (LC) to aggression. Both regions were previously associated with traumatic and chronic stress symptoms, yet it is unclear if their functionality represents a consequence of, or possibly also a cause for, stress symptoms. Here we investigated the relationship between the neural trajectory of these indicators of anger and the development and manifestation of stress symptoms. A total of 46 males (29 soldiers, 17 civilians) participated in a prospective functional magnetic resonance imaging experiment in which they played a modified interpersonal anger-provoking Ultimatum Game (UG) at two-points. Soldiers were tested at the beginning and end of combat training, while civilians were tested at the beginning and end of civil service. We assumed that combat training would induce chronic stress and result in increased stress symptoms. Soldiers showed an increase in stress symptoms following combat training while civilians showed no such change following civil service. All participants were angered by the modified UG irrespective of time point. Higher post-combat training stress symptoms were associated with lower pre-combat training vmPFC activation and with higher activation increase in the LC between pre- and post-combat training. Results suggest that during anger-provoking social interactions, flawed vmPFC functionality may serve as a causal risk factor for the development of stress symptoms, and heightened reactivity of the LC possibly reflects a consequence of stress-inducing combat training. These findings provide potential neural targets for therapeutic intervention and inoculation for stress-related psychopathological manifestations of anger.

Resilience and coping in trauma spectrum symptoms prediction: A structural equation modeling approach

Resilience is increasingly recognized as a relevant factor in shaping psychological response to natural disasters. Aim of the study is to examine in the context of a natural disaster the potential effects of resilience on the relation between coping and trauma spectrum symptoms, using structural equation modeling.A sample of 371 students who survived the earthquake in L’Aquila (Italy) were cross-sectionally evaluated using Resilience Scale for Adolescents, Brief Cope and Trauma and Loss Spectrum scale.The model shows a direct path of positive and emotional coping styles on resilience. Emotional coping shows also a direct impact on the outcome; positive and emotional coping results to be positively correlated as well as emotional and disengagement coping styles. Resilience directly affects the PTSD symptoms, partially mediating the impact of the coping styles. The model explains 30% of the variance in the outcome, i.e. the Post-Traumatic Stress Disorder (PTSD) symptoms, with very good fit indexes.Resilience operates as a protective factor from stress symptom development. It is likely that emotional and disengagement coping skills are rapidly involved after a traumatic exposure but when problem focused coping intervenes, resilience allows it to buffer the stressors or even guides toward a more successful outcome.

Understanding work related musculoskeletal pain: does repetitive work cause stress symptoms?

Background: Pain in the neck and upper extremity is reported with high frequency in repetitive work. Mechanical overload of soft tissues seems a plausible mechanism, but psychological factors have received...

Posttraumatic Stress Responses in Bereaved Children After the Oklahoma City Bombing

To investigate the responses of middle and high school students exposed to the 1995 Oklahoma City bombing across a spectrum of loss. A questionnaire measuring exposure, personal consequences, initial response, and current posttraumatic stress and other symptoms was administered to 3,218 students 7 weeks after the explosion. More than one third of the sample knew someone killed in the explosion. Bereaved youths were more likely than nonbereaved peers to report immediate symptoms of arousal and fear, changes in their home and school environment, and posttraumatic stress symptoms. Retrospective measures of initial arousal and fear predicted posttraumatic stress symptoms at 7 weeks. The results support the literature addressing the role of initial response in posttraumatic stress symptom development. The study raises concern about the impact of television, and traumatized youths' reactivity to it, in the aftermath of disaster.

A role for cyanide, derived from ethylene biosynthesis, in the development of stress symptoms

A role for cyanide, derived from ethylene biosynthesis, in the development of stress symptoms

A role for cyanide, derived from ethylene biosynthesis, in the development of stress symptoms

Cyanide is formed as a co‐product of ethylene during the oxidation of 1‐aminocyclo‐propane‐1‐carboxylic acid (ACC) catalyzed by ACC oxidase. A toxic or regulatory function for cyanide in plant metabolism remains controversial. However, recent studies on the mode of action of auxin herbicides in sensitive plants suggest that the accumulation of tissue cyanide, derived ultimately from herbicide‐stimulated ACC synthesis, is implicated in the induction of herbicide phytotoxicity. Furthermore, increases in cyanide levels have been observed during the formation of necrotic lesions in tobacco mosaic virus‐infected tobacco leaves. It thus appears worthwhile to elucidate in more detail a possible role for cyanide in the induction of cell death under stress conditions which coincide with a strong stimulation of ethylene biosynthesis.

Mental load and work stress as two types of energy mobilization

Abstract A conceptual framework is presented in which mental load and stress are regarded as two distinct biobehavioural states in the work environment that differ in energy mobilization, mood and coping strategy. The framework combines two types of theory that are based on human performance research using laboratory tasks on the one hand and applied research in the work environment on the other. A high workload is regarded as an important but not a critical factor in the development of stress symptoms. Even under unfavourable conditions it is possible to work intensively and to be highly activated without feelings of strain or psychosomatic complaints. In contrast, working conditions that provide few possibilities for control and little social support or are associated with reduced well-being and increased health risks. The two states differ in activation, coping style and mood. A proper distinction is important not only for theory building but also for the reconstruction of the work environment. It may lead to recommendations that aim to enhance the work efficiency of employees while reducing the probability that stress responses will occur.

Comparing the concepts of mental load and stress

This paper delineates mental load and stress as two related concepts that originate from different theoretical frameworks. A proper distinction between the two concepts is important, not only for theory building, but because it may lead also to different interpretations of experimental results, and, consequently, to different recommendations in applied situations. High workload is regarded as an important but not a critical factor in the development of stress symptoms. It is quite possible to work hard in difficult and complex tasks, even under unfavourable conditions, without cognitive strain, psychosomatic complaints, or adverse physiological effects. High task demands can be met by mobilizing extra energy through mental effort. This 'trying harder' reaction is a normal and healthy coping strategy to adapt to situational demands. In contrast, stress is regarded as a state in which the equilibrium between cognitive and energetical processes is disturbed by ineffective energy mobilization and negative emotions. Stress typically is characterized by inefficient behaviour, overreactivity, and the incapacity to recover from work. Stress is regarded as a state in which the physiological system is disorganized, which results in decreased well-being, sleeping problems, psychosomatic complaints, and increased health risks.

SALINITY STRESS RESPONSES OF MINIATURE DWARF TOMATO IN A WHOLE PLANT MICROCULTURE EVALUATION SYSTEM

A whole plant microculture (WPMC) screening system facilitated rapid, quantitative appraisal of salt stress effects on `Micro-Tom' miniature dwarf tomato. Axillary bud explants were micropropagated on a hormone-free control medium (conductivity = 3.3 dS m-1), gradually introduced to treatments with increasing NaCl or Na2SO4 concentrations via biweekly subculture to fresh media (7,6, 12.8, or 18 dS m-1), and monitored over a subsequent 5 week culture period. Non-intrusive video image analysis techniques were adapted to quantify morphometric (shoot growth rate, area, and length; root length and area) and photometric (ruler and tissue quality) plant responses. Shoot growth was only slightly inhibited at 7.6 and 12.8 dS m-1, but was severely stunted and distorted on high salt (18 dS m-1) media. Root growth inhibition (significantly shorter and thinner primary rants) was first evident at 12.8 dS m-1 after 3 weeks of treatment. At 18 dS m-1, conspicuous retardation of root growth relative to controls could be gauged after only one week. Shoot tip chlorosis was observed in the lowest salt-supplemented treatment after three to four weeks of culture, but overall shoot yellowing at the two highest conductivities was marked after only a few days. Chlorosis symptoms were not uniform within treatments. Cell osmotic concentration showed a linear increase with increasing medium salinity. The WPMC system expedited time course observations of stress symptom development, paralleled stress response trends observed in solution culture tests, and provided an excellent vehicle to investigate plant adaptation to saline conditions.

Effects of Ultraviolet-B Irradiation on Seedling Growth in the Pinaceae

Ten conifer species were grown in an unshaded greenhouse at the University of Maryland under 3 levels of biologically effective ultraviolet-B radiation. Ultraviolet-B radiation was supplied by Westinghouse FS-40 sunlamps and effective daily doses were 0, 12.4, and 19.1 kJ m–2. During the irradiation period, seedling growth and the development of stress symptoms were monitored. After 22 weeks of irradiation, seedlings were harvested and morphological characteristics analyzed. Visual symptoms included needle discoloration and stunting in three of the ten species tested. Seedling height was significantly reduced by supplemental UV-B in Pinus contorta (lodgepole pine), Pinus resinosa (red pine), and Pinus taeda (loblolly pine). Biomass increased in Picea engelmannii (Engelmann spruce). Abies fraseri (Fraser fir), Pinus edulus (pinyon pine), and Pinus nigra (black pine) were unaffected by UV-B while biomass reductions exceeding 5% were observed in all other species tested. These deleterious effects occurred despite the presence of morphological characteristics which would tend to reduce UV-B effectiveness. Generally, the effects of supplemental UV-B dose were less for those species native to higher elevations, implying the presence of natural adaptations to UV-B.

EFFECTS OF ULTRAVIOLET‐B IRRADIATION ON SEEDLING GROWTH IN THE PINACEAE

Ten conifer species were grown in an unshaded greenhouse at the University of Maryland under 3 levels of biologically effective ultraviolet‐B radiation. Ultraviolet‐B radiation was supplied by Westinghouse FS‐40 sunlamps and effective daily doses were 0, 12.4, and 19.1 kJ m–2. During the irradiation period, seedling growth and the development of stress symptoms were monitored. After 22 weeks of irradiation, seedlings were harvested and morphological characteristics analyzed. Visual symptoms included needle discoloration and stunting in three of the ten species tested. Seedling height was significantly reduced by supplemental UV‐B in Pinus contorta (lodgepole pine), Pinus resinosa (red pine), and Pinus taeda (loblolly pine). Biomass increased in Picea engelmannii (Engelmann spruce). Abies fraseri (Fraser fir), Pinus edulus (pinyon pine), and Pinus nigra (black pine) were unaffected by UV‐B while biomass reductions exceeding 5% were observed in all other species tested. These deleterious effects occurred despite the presence of morphological characteristics which would tend to reduce UV‐B effectiveness. Generally, the effects of supplemental UV‐B dose were less for those species native to higher elevations, implying the presence of natural adaptations to UV‐B.