Severely Stressed Research Articles

Personality traits and health-related behaviors in medical students facing a stressful event.

It is believed that personality traits have an impact on the propensity to change and maintain favorable lifestyle habits. This issue has been raised by multiple studies, however, none of them appeared to focus on population under severe psychological stress. The aim of the present study was to investigate the link between personality traits and health-related behaviors and measures such as dietary intake of specific food products, physical activity, body-mass index and the use of cigarettes in medical students facing a stressful event. The study included a cohort of third-year medical students from the Medical University of Lodz, Poland, facing a stressful subject exam during the first COVID-19-related lockdown. At baseline, personality traits were evaluated with the use of the Polish version of the Big Five Inventory-Short questionnaire. Then, consumption of selected food products was monitored with the use of seven-day electronic dietary record. Also, some other health-related data was collected (body-mass index, physical activity and the use of cigarettes). General Linear Modeling techniques, logistic regression and exploratory factor analysis were applied to analyze the data. Four hundred and forty-four students completed the study. A two-factor pattern of food consumption was discovered by the exploratory factor analysis in the study group (34% of the variance explained). Higher conscientiousness, but not the other personality traits, was found to be significantly associated with generally healthier lifestyle manifested by higher consumption of vegetables, wholegrain products, fruits and nuts (adjusted beta 0.16, 95%CI 0.06 to 0.26, pη2 = 2.3%, p = 0.0015) and lower cigarette smoking (adjusted odds ratio 0.84, 95%CI 0.75 to 0.94, p = 0.0020), but insignificantly with physical activity and body-mass index. Severely stressed medical students expressing high conscientiousness tend to present healthier behaviors. Therefore, interventions aimed at improving lifestyle habits in students with low conscientiousness might be useful.

Response of Cyclopia subternata to drought stress – assessment of leaf composition, proteomics and product quality

Honeybush tea is made from the fynbos plant Cyclopia subternata, which is unique to South Africa. Cultivation takes place in its natural environment, which has a Mediterranean climate with dry summers and wet winters. During the summer, the plant is vulnerable to drought, an abiotic stress factor that is likely to affect its development and yield. This study investigated the effect of drought stress for a short duration on the leaf, as well as the quality of the herbal tea. Protein expression in the leaf was measured to gain insight into possible mechanisms used by the plant to cope with drought stress conditions. Fifteen-month-old C. subternata plants were subjected to three water treatments (control, moderately-stressed (MS), and severely-stressed (SS)) for ten days. Leaves were sampled at regular intervals throughout the treatment period to determine their relative water content (RWC). Leaves were also sampled on the 11th day for untargeted and targeted chemical composition and protein expression analyses. The remaining leaves and stems were processed to obtain the herbal tea. Descriptive sensory analysis of the herbal tea was performed to determine whether drought stress affected product quality. RWC was substantially higher (p < 0.05) in the control plants (100%) than in the MS and SS treated plants (83–90% and 47%, respectively). Untargeted analysis revealed that drought stress considerably altered leaf chemical composition. According to targeted analysis, the proline content of SS treated plants increased more than 40-fold when compared to the control, however, the treatments had no effect on the total carbohydrate and major phenolic compound content of the leaves, nor on the sensory quality of the herbal tea. Differences in the expression of 27 proteins, 24 of which were identified using proteomic analysis, were observed. During drought stress, 17 of these proteins increased, whereas seven decreased. Thirteen of the 24 identified proteins produced statistically significant results based on their Byonic scores. The findings laid the foundation for future research into the functions of drought response genes in Cyclopia species, as well as helping with the identification of stress-tolerant honeybush genotypes.

Application of creatinine height index in patients with trauma for the evaluation of psoas muscle mass: A clinical validation study.

The creatinine height index (CHI) is an estimate of lean body mass. We hypothesize that a modified CHI estimate using serum creatinine (sCr) levels in patients with normal renal function when performed soon after injury would reflect preinjury protein nutrition status. The urine CHI (uCHI) was calculated using the 24-h urine sample. The serum-derived estimated CHI (sCHI) was calculated using the sCr on admission. Correlation between abdominal computed tomographyimages at specific lumbar vertebral levels and total body fat and muscle content was used for comparison as an independent measurement of nutrition status unlikely to be substantially altered by trauma. A total of 45 patients were enrolled, all with a significant injury burden (median injury severity score [ISS] = 25; interquartile range, 17-35). The calculated sCHI on admission was 71.0% (SD = 26.9%) and likely underestimates the CHI when compared with uCHI (mean = 112.5%, SD = 32.6%). Stratifying by degree of stress demonstrated that in a group of 23 moderately and severely stressed patients, uCHI (mean = 112.7%, SD = 5.7%) and sCHI (mean = 60.8%, SD = 1.9%) were significantly different and without correlation (r = -0.26, P = 0.91). In patients without stress, there was a significant negative correlation between sCHI and psoas muscle area (r = -0.869, P = 0.03), and in patients with severe stress there was a significant positive correlation between uCHI and psoas muscle area (r = 0.733, P = 0.016). The CHI calculated from the initial sCr is not an appropriate estimate of uCHI in critically ill trauma patients and is not a valid measure of psoas muscle mass in this setting.

Characterisation and Effects of Different Levels of Water Stress at Different Growth Stages in Malt Barley under Water-Limited Conditions.

Malt barley is typically grown in dryland conditions in South Africa. It is an important grain after wheat, but little is known about its water requirements and, most importantly, how it responds to water stress. Determining when water stress sets in and how malt barley responds to water deficit during its growing season is crucial for improved management of crop water requirements. The objectives of this study were to evaluate the response of transpiration (T), stomatal conductance (SC), and leaf water potential (LWP) to water stress for different growth stages of malt barley and to characterise water stress to different levels (mild, moderate, and severe). This was achieved by monitoring the water stress indicators (soil- and plant based) under greenhouse conditions in well-watered and water-stressed lysimeters over two seasons. Water stress was characterised into different levels with the aid of soil water content ‘breaking points’ procedure. During the first season, at the end of tillering, flag leaf, and milk/dough growth stages, which represent severe water stress, plant available water (PAW) was below 35%, 56%, 14%, and 36%, respectively. LWP responded in accordance to depletion of soil water during the growing season, with the lowest recorded value to −5.5 MPa at the end of the milk/dough growth stage in the first season. Results also show that inducing water stress resulted in high variability of T and SC for both seasons. In the second season, plants severely stressed during the anthesis growth stage recorded the least total grains per pot (TGPP), with 29.86 g of grains. The study suggests that malt barley should be prevented from experiencing severe water stress during the anthesis and milk/dough stages for optimum malt barley production. Quantification of stress into different levels will enable the evaluation of the impact of different levels of stress on the development, growth, and yield of barley.

Early gene expression response of barley root tip to toxic concentrations of cadmium

Already a short-term Cd treatment induces changes in gene expression in barley root tips via IAA and ROS signaling during mild and severe Cd stress, respectively. Even a short, 30min, Cd treatment of roots induced a considerable alteration in gene expression in the barley root tips within an hour after the treatments. The very early activation of MYB1 transcription factor expression is partially regulated by auxin signaling in mildly stressed seedlings. An increase in allene oxide cyclase and NADPH oxidase expression was a distinguishing feature of root tips response to mild Cd stress and their expression is activated via IAA signaling. Meanwhile, early changes in the level of dehydrin transcripts were detected in moderately and severely stressed root tips, and their induction is related to altered ROS homeostasis in cells. The early activation of glutathione peroxidase expression by mild Cd stress indicates the involvement of IAA in the signaling process. In contrast, early ascorbate peroxidase expression was induced only with Cd treatment causing severe stress and ROS play central roles in its induction. The expression of cysteine protease was activated similarly in both mildly and severely Cd-stressed roots; consequently, both increased IAA and ROS levels take part in the regulation of cysteine protease expression. The Cd-evoked accumulation of BAX Inhibitor-1 mRNA was characteristic for moderately and severely stressed roots. Whereas decreased IAA level did not affect its expression, rotenone-mediated ROS depletion markedly reduced the Cd-induced expression of BAX Inhibitor-1. An early increase of alternative oxidase levels in the root tip cells indicated that the reduction of mitochondrial superoxide generation is an important component of barley root response to severe Cd stress.

Psychological Impact of the COVID-19 Pandemic on Students, Assistants, and Faculty of a Dental Institute of Saudi Arabia.

This study aimed to assess the perceived stress levels in students, assistants, and faculty members of the College of Dentistry, Imam Abdulrahman Bin Faisal, University (IAU), Kingdom of Saudi Arabia (KSA) during the novel coronavirus disease 2019 (COVID-19) pandemic. Using the Cohen’s perceived stress scale (PSS) questionnaire (consisting of 14 items, hence called PSS-14), an online observational survey was conducted. The PSS 14 was rated on a 5-point Likert scale ranging from 0 (never) to 4 (very often). The scores ranging from 0–18 represented low stress, 19–37 represented moderate stress, and 38–56 represented high stress. The second-and third-year students were designated as junior year students, while fourth-year onwards were considered senior year students. Out of total 265 participants, 65% (173) were female, and the majority of the participants were dental students 70% (185) with a mean age of 26.71 ± 9.26 years. In the present study, the average PSS score for the participants was computed as 29.89 (range score: 0–56) which shows moderate stress levels among the respondents. The PSS score for the students was 31.03; for the faculty, it was 28, while for the assistants, it was 27.05. Among the three participant groups, the students were found more on the severe stress side (19%) (p-value = 0.002), and among them, the senior year students (6th year) showed significantly higher stress levels compared to the junior year students (p-value = 0.005). Age-wise, the participants below 20 years were most stressed (21%), followed by those 20–30 years old (18%). Female participants were more severely stressed than males (17% vs. 10%, respectively). It was concluded that the students experienced more stress, followed by the faculty members and dental assistants. In addition, younger participants, females, and senior year students were more stressed than their counterparts. Future studies directed at evaluating stress levels of these groups from different dental institutes could provide an opportunity for policymakers to offer various resources to improve their mental health.

Learning Environment Quality for Medical Students at Umm Al-Qura University: A Comprehensive Study on Stressors, Sources, and Solutions After Introduction of a New Bachelor of Medicine and Bachelor of Surgery (MBBS) Curriculum.

ObjectiveDue to introduction of a new curriculum and the related stressors that medical students might encounter, we aimed to assess the quality of the students’ learning environment across academic years at Umm Al-Qura University (UQU), by evaluating stress levels, their sources, and impacts on students, to help improve the quality of learning environment and protect students from personal and academic burnout.MethodsWe conducted a descriptive cross-sectional study in August and September of 2020 on 572 students enrolled in the new Bachelor of Medicine and Bachelor of Surgery (MBBS) curriculum at UQU. All statistical analyses were performed using SPSS software and two-tailed tests.ResultsIn total, 46.5% of participants encountered severe stress levels during their studies at UQU. In term of stressor sources, the highest prevalence of severe stress was found among students who lacked learning resources (68.8%), followed by those who complained of ambiguity in teaching, learning, and assessment strategies (64.1%). Self-study strategy issues (58.4%) and difficulty in reading textbooks (58.2%) also ranked high. Anxiety was often reported by the students as an impact of stress (62.9%), followed by mood swings (60%). Severe stress levels showed a statistically significant relationship to gender, being highest among females (P = 0.001). For a solution to manage the stress, 79% of the students suggested a supportive learning environment and identification of students’ struggles at early stages.ConclusionAlmost half the medical students were severely stressed after the new curriculum was introduced. Therefore, professors and universities should look out for potential stressors and help students overcome them. Universities can also help by offering counseling services to students, improving the student tutoring system, providing appropriate learning environment and resources, and including stress management courses as a part of the overall curriculum.

Prevalence of depression, stress, anxiety among information technology professionals during COVID-19 lockdown, 2020 in Kerala

Background: COVID-19 pandemic has completely changed the work pattern of information technology professionals who had to shift from the work from office to work from home pattern. The comforts of home, that they used to enjoy, was now taken up by an office space at home and this has potentially altered the mental health status of these professionals.Methods: A cross sectional study was conducted among IT professionals within the age group 21-45 years working in Kerala. 218 subjects were included in the study. A self-prepared structured questionnaire was used to collect basic demographic information and depression anxiety and stress scale (DASS 21) scale was used to assess depression anxiety and stress among IT professionals using Google form. Informed consent was obtained in the beginning of the questionnaire. The data was entered in Microsoft Excel and analysed using SPSS software.Results: Out of the total study participants 50.5% (110) were males and 49% (108) were females. 42.7% were married and 57.3% were unmarried and none of them were divorced or living separated. Most of the study participants (62.8%) had monthly income below 50,000. Out of the total study participants, 72 (33%) of them were working in IT field for less than 2 years, 52 were working for last 2-4 years, 51 were working for last 4-8 years and only 43 individuals were working for more than 8 years. 67% of them had their working hours raised during COVID lock down. In our study while 21.6% had a previous history of psychiatric illness for which they have consulted a doctor/psychologist. Out of all the study subjects, 4.1% were mildly depressed, 6.9% were moderately depressed, 5.5% were severely depressed and 1.8% had extremely severe depression. Most of the study subjects (81.7%) were not anxious, 9.2% were mildly anxious, 6.8% were moderately anxious, 2.3% were severely anxious. 76.9% had no stress, 6.1% were mildly stressed, 11.5% were moderately stressed, 4.6% were severely stressed and 0.9% had extremely severe stress. Depression among IT professionals during COVID-19 lockdown was found to be significantly associated with past history of psychiatric illness. Anxiety was found to be significantly associated with past history of psychiatric illness and unmarried relationship status. The stress among IT professionals during lockdown was found to be significantly associated with previous history of psychiatric illness and unmarried relationship status.Conclusions: 18.3% of the IT professionals had some degree of depression and 23.1% was facing stress 18.3% was anxious. Past history of psychiatric illness was associated with increased depression anxiety and stress. Unmarried relationship status was associated with associated with increased anxiety and stress.

Intermittent moisture supply induces drought priming responses in some heat‐tolerant chickpea genotypes

AbstractHeat and drought stresses are two abiotic factors that often occur simultaneously and are predicted to increase, consequently hampering plant growth. Response of different species to either stresses is well documented but information on the response of the same genotypes to both stresses in chickpea (Cicer arietinum L.) is limited. We aimed to determine whether previously noted heat‐stress‐tolerant genotype (Acc#7) is drought tolerant, that heat‐sensitive genotype (Acc#8) is drought sensitive, and whether intermittent moisture supply at vegetative stage would induce priming effect to later drought at flowering. At vegetative stage, plants were divided into three groups, nonstressed (watered to 75% field capacity [FC], severe water stress (moisture withholding for 14 d), and treated to 40% FC throughout the experiment (mild stress), with recovery for the severely stressed plants after which they were stressed (double stress) at flowering. Drought treatments at vegetative and flowering growth stages decreased physiological parameters and biomass accumulation in both genotypes except low water supply at 40% FC that decreased biomass in Acc#7 but not Acc#8. Double‐drought stress resulted in priming effect in Acc#7, having higher biomass, chlorophyll fluorescence, stomatal conductance (gs), net photosynthesis, and relative water content (RWC) vs. the introduction of stress only at flowering growth stage as well as in comparison with Acc#8. These results showed that both Acc#7 and Acc#8 are sensitive to drought, whereas after priming, Acc#7 is better acclimated to drought than Acc#8 associated with osmotic adjustment on leaf RWC and higher capacity to protect photosynthetic activity, making Acc#7 potentially ideal for areas associated with intermittent drought spells.

Pulsed drought: The effects of varying water stress on plant physiology and predicting herbivore response

AbstractClimate change is predicted to increase the frequency of drought conditions and alter plant–insect interactions. Despite over 530 studies on the effects of water‐deficit stress on plant–insect interactions, we still cannot accurately predict plant–insect interactions under drought conditions. Most studies have focused on how insect herbivores respond to water‐deficit‐stressed plants, with little attention on how stressed plants and changes in plant physiology may contribute to the variation in herbivore response. Variation in herbivore response to water‐deficit‐stressed plants may be due to stress‐induced changes in plants and how these changes differ with stress severity. In this study, we determined the effects of water‐deficit stress on cotton (Delta Pine 174RF) physiology in an agroecosystem using pulsed moderate and severe stress. Our goal was to determine how moderate and severe water‐deficit stress affect cotton (Gossypium hirsutum L.) physiology differently in terms of photosynthesis, development, water use, and nutrient content. We found that moderate and severely stressed plants had many different physiological responses that may contribute to the variation we see in herbivore response to stressed plants. For instance, moderately stressed plants were more vigorous and more developed than severely stressed plants, whereas severely stressed plants had more amino acids than moderately stressed plants. We predict that insect herbivores feeding on moderately and severely stressed plants would encounter differences in C assimilation, water content (stomatal conductance, transpiration), chlorophyll content, and concentrations of amino acids and digestible carbohydrates. It is clear that field studies should consider how differences in stress severity can affect plant–insect interactions.

The resistance and resilience of European beech seedlings to drought stress during the period of leaf development.

Spring drought is becoming a frequently occurring stress factor in temperate forests. However, the understanding of tree resistance and resilience to the spring drought remains insufficient. In this study, European beech (Fagus sylvatica L.) seedlings at the early stage of leaf development were moderately and severely drought stressed for 1 month and then subjected to a 2-week recovery period after rewatering. The study aimed to disentangle the complex relationships between leaf gas exchange, vascular anatomy, tree morphology and patterns of biomass allocation. Stomatal conductance decreased by 80 and 85% upon moderate and severe drought stress, respectively, which brought about a decline in net photosynthesis. However, drought did not affect the indices of slow chlorophyll fluorescence, indicating no permanent damage to the light part of the photosynthetic apparatus. Stem hydraulic conductivity decreased by more than 92% at both drought levels. Consequently, the cambial activity of stressed seedlings declined, which led to lower stem biomass, reduced tree ring width and a lower number of vessels in the current tree ring, these latter also with smaller dimensions. In contrast, the petiole structure was not affected, but at the cost of reduced leaf biomass. Root biomass was reduced only by severe drought. After rewatering, the recovery of gas exchange and regrowth of the current tree ring were observed, all delayed by several days and by lower magnitudes in severely stressed seedlings. The reduced stem hydraulic conductivity inhibited the recovery of gas exchange, but xylem function started to recover by regrowth and refilling of embolized vessels. Despite the damage to conductive xylem, no mortality occurred. These results suggest the low resistance but high resilience of European beech to spring drought. Nevertheless, beech resilience could be weakened if the period between drought events is short, as the recovery of severely stressed seedlings took longer than 14days.

Genetic and physiological analysis of early drought response in Manihot esculenta and its wild relative

Cassava (Manihot esculenta) is a staple food crop mostly grown in the tropics. Successful cultivation in marginal areas derives from its ability to withstand difficult environmental conditions. Aiming at providing new insights into drought tolerance in Manihot spp., we performed physiological and molecular analyses of early drought response in three cassava varieties and in the wild species, Manihot glaziovii (manicoba). Plants grown in pots were subjected to three water regimes for 5 days, based on soil field capacity (FC): 75% (well-watered plants); 45% (moderately stressed plants), and 20% (severely stressed plants), under greenhouse condition. Analysis of leaf gas exchange showed a downward trend in photosynthesis, stomatal conductance, and transpiration, with intensification of the stress, in all genotypes, being significantly reduced only at 20% FC. Manicoba stood out for maintaining a positive carbon balance in severe stress condition via stomatal aperture control. Photoinhibition of the photosystem II by drought was also evident only at 20% FC. There was no clear association between proline accumulation and drought stress tolerance. Expression analysis of nine genes encoding heat-shock proteins, transcription factors, a cell redox homeostasis protein, and a no-hit protein confirmed the activation of classical stress-responsive pathways, especially those involved in oxidative damage avoidance. These results reinforce the intrinsic drought tolerance of cassava, highlight the superior performance of manicoba under water deficit conditions, and give insights into drought phenotyping in cassava and contribute to further development of functional molecular markers to be used in assisted breeding.

Characteristics of Student– Dog Interaction during a Meet-and-Greet Activity in a University-Based Animal Visitation Program

ABSTRACTThe use of university-based Animal Visitation Programs (AVPs)—programs aimed at reducing student stress through human–animal interaction (HAI)—has increased. Implementation has expanded despite our limited understanding about program effects on student and animal wellbeing. Moreover, little is known about the nature of interactions between students and animals and how interaction quality might influence effects. The aim of this study was to identify and describe dog and student behaviors that inform the quality, type, and quantity of human–animal interaction during a university-based AVP. Over a period of three semesters, university students (n = 150) and therapy dogs (n = 27) were videorecorded during a 10-minute “meet-and-greet” activity conducted in small group settings. Based on coding 22.9 hours of 135 videos, comparisons of the frequency and duration of dog behavior (e.g., postural state, oral behavior) before and during interactions with students revealed an increase in the frequency of lip licking (Mbefore = 1.23, Mduring = 1.76, Z = –4.651, p < 0.001, r = 0.283) and yawning (Mbefore = 0.08, Mduring = 0.16, Z = –3.051, p = 0.002, r = 0.186) in dogs. Correlations between dog and student greeting behavior (e.g., posture, petting behavior) revealed a positive correlation between the frequency of lip licking and mutual greetings between students and dogs (r(133) = 0.283, p = 0.001). Results suggest dogs experience heightened arousal upon greeting and interacting with students. The absence of severe stress behaviors and continued presence of sustained social approach behaviors suggests that the dogs were not severely stressed during interactions. Implications for the implementation of AVPs are discussed.

Effect of vitamin B6 supplementation, in combination with magnesium, on severe stress and magnesium status: secondary analysis from an RCT

AbstractIntroductionEvidence from a recent randomised controlled trial1 suggests that in severely stressed subjects with low magnesemia, supplementation with magnesium (Mg) in combination with vitamin B6 (B6) provides greater benefits than Mg alone. B6 was reported to facilitate Mg absorption and its cellular uptake and to exert synergistic effect with Mg. The current secondary analysis explored the relationship between Mg-B6 combination and erythrocyte Mg concentration, used as a biomarker of body Mg status.Material and MethodsAn 8-week, Phase IV, controlled, single-blinded, parallel-group trial (EudraCT Number 2015-003749-24) stratified by sex was conducted in adults (n = 264) with a Depression Anxiety Stress Scales - stress subscale score (DASS-42SS) &gt; 18 and serum Mg of 0.5–0.85mmol/L, randomised 1:1 to daily oral Mg-B6 (Magne B6®, Mg 300 mg; B6 30mg) or oral Mg alone (Magnespasmyl®, Mg 300mg). Outcomes were stress score, serum Mg (mmol/L), erythrocytes Mg (mmol/L), and serum B6 (nmol/L) from baseline to Week4 and Week8. Data are given as mean(SD) values.Results &amp; DiscussionBaseline characteristics. Baseline magnesemia was 0.80(0.04) for both groups. Erythrocyte Mg concentration for the lower quintile of the studied population (n = 53) was 0.73–1.62, below the normal range of 1.65–2.65 in general population. The mean stress score in this subgroup was higher [29.5(6.3)], but not significantly different from that in other quintiles [lowest value: 26.1(7.6)]. Baseline B6 serum level for the lower B6 quintile (5–23), below the normal range for general population, was suggestive of possible B6 deficiency.Treatment effects. Both treatments increased slightly but not significantly erythrocyte Mg level from baseline to Week8 [1.84(0.03) to 1.86(0.03), and 1.86(0.03) to 188(0.03), respectively for Mg + B6 and Mg groups]. Significant changes were observed in subjects with low erythrocyte Mg level at baseline (&lt; 1.6), namely an increase of + 0.13(0.04–0.22) for Mg + B6 and + 0.17(0.08–0.25) for Mg groups, but with no difference between treatments. Moreover, Mg + B6 supplementation led to a significant change (p &lt; 0.0001) in serum B6 level between baseline and Wk8 [55.9(4.8) to 370.9(11.3)], as compared to Mg alone [51.9(4.8) to 51.5(11.3)].In conclusion, both treatments significantly increased erythrocyte Mg in subjects with low Mg status. B6 supplementation did not lead to further increase in erythrocyte Mg level. We have previously shown that severely stressed population benefits from B6 supplementation in combination with Mg, however, the mechanism of the interaction between Mg and B6 remains to be elucidated.1Sponsored by Sanofi

College Academic Stress: Getting by, Muddling Through

Academic stress challenges students’ ability to cope up and strategize. In the University, manifestation of moderate stress along academic endeavors among future teachers should not be disregarded as when this becomes critical. It will burden their academic journey and personal lives. Using descriptive research design employing descriptive and inferential statistics, the study unveiled that students are severely stressed along financial-related matters, which calls for their capacity to budget allowance, deal with unexpected expenses and save money for requirements. Submitting requirements, dealing with strict teachers, bearing with noisy classrooms, transferring from one building to the other and worrying about future cause them severe stress but they are not stressed at attending classes. Coping styles are often used by students to manage stress. Thinking of the brighter side of life and trying to rediscover the most important things in life are indications of optimism among students. Year level, among other profile variables, significantly influences the students’ academic stress levels. Sophomores were significantly more stressed than the seniors. Though relationship between academic stress and coping styles was not significantly established, it is quite essential that students are taught on coping mechanisms, so they have defense against stress. Keywords : college academic stress, getting by/muddling through, coping styles/strategies, stress levels, future secondary school teachers

Systemic Granulomatous Pathology in Two Captive Alligator Mississippiensis

Abstract The literature in this field cites various ubiquitous fungal and bacterial microorganisms as etiologic agents in severely stressed captive alligators and crocodiles. This study reports two cases of Alligator mississippiensis with bacterial and fungal disease. Two adult American alligators have been submitted for post-mortem investigations. Necropsy, cytology (MGG), and histopathology investigations (HE, HEA, PAS, Gram, Giemsa, Ziehl Neelsen) were carried out. Pleural and pericardial swabs were subjected to microbiological examination. The main lesions detected involved the lower respiratory system and were characterized by thoracic serosanguineous effusions, pleural and pulmonary nodules (1 – 80 mm), accompanied by edema. Similar nodules observed also in the liver, spleen and myocardium, suggested a systemic disease. Additionally, cutaneous, gingival and gastrointestinal erosions and ulcers were found. Cytoarchitecture findings in the major organs revealed lymphoid depletion, multifocal to coalescing necrotic areas with coccoid aggregates and rod shaped bacteria intermixing fungal structures, boarded by heterogeneous inflammatory infiltrates, composed by epithelioid macrophages, lymphocytes and heterophils. The microbiological examination revealed the presence of Aeromonas hydrophila, A. caviae, Serratia marcescens, Pantoea agglomerans, Proteus vulgaris, haemolitic and non-haemolitic E. coli, Citrobacter freundii, Rhizopus/Absidia from pleural and pericardial cavities, concluding that death occurred following a bacterial and fungal pneumonia, with secondary spreading of microorganisms. Along with the low immune response, severe stress was the main possible cause, as a result of environmental temperature changes during the winter, as well as other husbandry issues.

Drought Exacerbates Botryosphaeria Dieback Symptoms in Grapevines and Confounds Host-based Molecular Markers of Infection by Neofusicoccum parvum.

Neofusicoccum parvum, causal fungus of the grapevine trunk disease Botryosphaeria dieback, attacks the wood of Vitis vinifera. Because lesions are internal, using putative host-based markers of infection from leaves for diagnosis is a nondestructive option. However, their specificity under drought stress is unknown. Potted 'Cabernet-Sauvignon' were inoculated with N. parvum in the greenhouse after wounding (IW), and with wounded and nonwounded noninoculated controls. At 2 weeks postinoculation (WPI), half of the plants were severely stressed (SS), receiving 30% water volume of the well-watered (WW) plants. Larger lesions at 12 WPI among IW-SS plants, compared with all other treatments, revealed an interactive effect of inoculation and drought on lesion length. Expression of eight putative marker genes was analyzed in leaves by qPCR at the onset of drought stress, and at 8 and 12 WPI. One marker showed consistent over-expression at 8 WPI in IW plants, regardless of water treatment, suggesting specificity to infection. By 12 WPI, higher expression of seven genes in all SS plants (across inoculation treatments) revealed specificity to drought. Cross-reactivity of markers to drought, therefore, limits their utility for disease diagnosis in the field, where drought induced by climate and deficit irrigation is common.

米槁幼苗光合作用及光响应曲线模拟对干旱胁迫的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 米槁幼苗光合作用及光响应曲线模拟对干旱胁迫的响应 DOI: 10.5846/stxb201802140372 作者: 作者单位: 贵州大学林学院,贵州大学林学院,贵州大学林学院,贵州大学林学院 作者简介: 通讯作者: 中图分类号: 基金项目: 贵州省科技计划（黔科合SY[2015]3023-1） Simulated photosynthetic responses of Cinnamomum migao during drought stress evaluated using Light-response Models Author: Affiliation: Guizhou University College of Forestry,Guizhou University College of Forestry,Guizhou University College of Forestry,Guizhou University College of Forestry Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为阐明米槁光合作用对干旱胁迫的响应规律与适应机制，以一年生米槁幼苗为研究对象，进行盆栽试验研究设置3种不同土壤含水量梯度，利用Li-6400便携式光合作用系统测定干旱胁迫下的光合生理指标及光响应过程，光响应曲线模拟采用直角双曲线模型、非直角双曲线模型、指数模型和直角双曲线修正模型进行拟合并对比，以期选出适用于干旱环境下的光响应模型。结果表明（1）光响应曲线模型对干旱胁迫下米槁幼苗的光合作用拟合中直角双曲线、非直角双曲线和指数模型适用于低光合有效辐射（PAR），但拟合光响应参数与实测值相差大，只有直角双曲线修正模型能够很好的拟合各个处理且拟合参数比较精确米槁幼苗。（2）光合作用的表观量子效率（Φ）小于一般植物的光合量子效率，则其对弱光的光能利用效率相对较低。（3）在较强的光合有效辐射条件下，严重干旱胁迫下的米槁净光合速率Pn显著下降，出现了明显的光抑制现象；中度胁迫下净光合速率（Pn）、最大净光合速率（Pnmax）、光补偿点（LSP）最大，米槁具有较宽的抗旱适应范围，有一定的抗旱性；严重胁迫下Pn、Pnmax、LSP降低，蒸腾速率（Tr）与气孔导度（Gs）下降幅度更大，但仍具有较高的水分利用效率（WUE），米槁在严重的干旱胁迫下光合机构受到一定的损伤，但自身可以通过生理调节来积极适应不良环境，减少光合机构伤害。（4）综合来看，在人工管理或种植米槁时，为了适应米槁生长发育，建议土壤含水量保持在23.05%到14.92%之间。 Abstract:The objective of this study was to elucidate the response and adaptation mechanisms of Cinnamomum migao seedlings to drought stress. Using pot experiments, we examined the effects of three relative water levels on the growth of 1-year-old C. migao seedlings by measuring photosynthetic physiological indices and light responses under drought stress. The responses were analyzed in terms of four different light response curve models:rectangular hyperbola, non-rectangular hyperbola, exponential, and modified rectangular hyperbola. The following results were obtained. (1) According to the values of photosynthetic parameters calculated using the four models, the rectangular hyperbola, non-rectangular hyperbola, and exponential models were suitable for low photosynthetically active radiation. However, only the modified rectangular hyperbola model provided a good fit for each treatment and the fitting parameters were more accurate. (2) The apparent quantum efficiency (Φ) of photosynthesis of drought-stressed plants was smaller than that of normal plants, and therefore the utilization efficiency of these plants is lower. (3) The net photosynthetic rate (Pn) of severely stressed C. migao plants decreased significantly under strong photosynthetically active radiation, whereas values for the net photosynthetic rate (Pn), maximum net photosynthetic rate (Pnmax), and light compensation point were the highest under conditions of moderate stress. C. migao has a wide range of stress tolerance. Under severe stress, Pn, Pnmax, and LSP decreased, and transpiration rate (Tr) and stomatal conductance (Gs) decreased more significantly; however, the plants still had a higher water-use efficiency. Although C. migao plants suffer damage under severe drought stress, they can adjust to the adverse environments through physiological modification and by reducing damage to their photosynthetic apparatus. (4) In order to facilitate growth and developmental adaptation in C. migao during management, it is recommended that the soil moisture content be maintained at levels between 23.05% and 14.92%. 参考文献 相似文献 引证文献

Influence of arbuscular mycorrhizal fungi inoculation on the control of stomata functioning by abscisic acid (ABA) in drought-stressed olive plants

Abscisic acid (ABA) is the key phytohormone modeling the stomata behavior under drought conditions. However, stomata closure is not correlated with leaf ABA content in mycorrhizal olive plant. The aim of the present study is to evaluate the impact of arbuscular mycorrhizal (AM) symbiosis on the control of stomata functioning by ABA in two olive tree (Olea europaea L.) cultivars ‘Zarrazi’ and ‘Meski’ subjected to dehydration–rehydration treatment. AM-inoculated (Myc+) and non-inoculated (Myc-) olive plants were subjected to water stress and then rewatered (recovery). Leaf ABA content, stomatal conductance and transpiration rate were measured in: (1) irrigated control, (2) moderately and severely stressed and (3) recovered plants. In both Zarrazi and Meski Myc– plants, ABA content increased in parallel with drought intensity and stomatal closure. However, an intra-specific variability appeared in inoculated plants; in Meski Myc+ plants ABA content was not influenced by drought and recovery treatments, whereas in Zarrazi Myc+ plants the ABA amount increased under moderate water stress and even further after water relief, but decreased under severe water stress. However, in Myc+ plants of both cultivars, stomatal closure was not correlated with leaf ABA content. The results reveal that the ABA is not the key factor controlling the stomatal closure in AM-inoculated olive plants under drought conditions. In fact, other AM-related factors are involved in the control of stomata regulation in mycorrhizal olive plants exposed to severe drought. These factors act specifically in the drought-resistant cultivar ‘Zarrazi’ permitting a suitable stomata behavior.

Perceived stress and source of stress among undergraduate medical students of Government Medical College, Mysore

Background: Stress is defined as a condition or feeling experienced when a person perceives that demands exceed the personal and social resources the individual is able to mobilize. Medical school is recognized as a stressful environment that may have a negative effect on students’ academic performance, physical health, and psychosocial well-being. This stress when it exceeds the limit of tolerability causes various physical and mental health problems. Identifying this root cause will help us to put a barrier to many future mental health problems in a student’s life.Methods: It was a cross-sectional study done in Mysore Medical College among undergraduate students. Perceived stress scale was used to assess the level of stress and Medical student’s Stressor questionnaire was used to assess the source of stress.Results: A total of 303 students were included in the final analysis. Among them 51.5% were male and 48.5% were females. The age group of the students ranged between 18 and 24 with a mean age of 20.48 and standard deviation (SD) of 0.4. The mean and SD of PSS score is 17.7 and 5.5. The prevalence of mild, moderate and severe stress was 20%, 74% and 6% respectively. Majority of the students (40.9%) considered academic related stressors to be the source of high stress.Conclusions: In our study though majority of the students were stressed (80%), only 6% were severely stressed. The coping strategies adopted by the students like resorting to sleep and music/dance appeared to be appropriate methods of handling stress.